GARTH, Circuit Judge:
OPINION OF THE COURT
This action, brought by employees who had participated in individual account pension plans maintained by their employer Unisys Corporation (“Unisys”), charged essentially that Unisys and the individual defendants1 had breached their fiduciary duties prescribed by ERISA2 by investing in Executive Life Insurance Guaranteed Investment Contracts (“GICs”). After a bench trial, the District Court granted judgment for all defendants, ruling in their favor on all issues related to the breach of fiduciary duty claims, thus denying all relief and damages to the plaintiff class of Unisys employees.3
We have reviewed the trial record independently and conclude that in all material respects, the District Court’s findings of fact were not clearly erroneous, the District Court did not abuse its discretion in excluding Dr. Gottheimer’s testimony, and the District Court did not err in making its conclusions of law. We also conclude that while we do not agree with some of the holdings of the District Court, those disagreements have no effect on the District [149]*149Court’s overall holding of prudence, and that therefore, the orders entered by the District Court on November 24, 1997 and January 9,1998 will be affirmed.
I.
This is the second appeal from the District Court’s rulings in this case. Initially, summary judgment was entered in favor of Unisys, but on review, we remanded for trial. In re Unisys Savings Plan Litig., 74 F.3d 420 (3d Cir.), cert. denied, 519 U.S. 810, 117 S.Ct. 56, 136 L.Ed.2d 19 (1996) (“Unisys /”). Almost all of the background facts and details are found in our earlier opinion and we refer here only to those matters particularly relevant to the arguments made by the parties on appeal.
Now that the District Court has rendered its findings of fact and conclusions of law in favor of the Unisys,4 Meinhardt complains that the standard used by the District Court was improper, that Mein-hardt’s expert’s testimony was improperly excluded, and that Meinhardt suffered damages that were not recognized by the District Court. As indicated above, we hold that the District Court’s essential factual findings were not clearly erroneous and that measured by the appropriate prudence standard of ERISA, the District Court properly concluded that Unisys did not breach any fiduciary duty. This threshold holding makes it unnecessary for us to discuss in detail the subsidiary issues raised on appeal by Meinhardt.
At the outset we call attention to the fact that the contours of the factual record have changed significantly since we last addressed the GIC issue presented in this case. At the earlier summary judgment stage, the prior panel of this court was obliged to assume that various facts presented by Meinhardt were true and that all inferences had to be drawn in Mein-hardt’s favor. Moreover, we assumed the report of Dr. Gottheimer, Meinhardt’s proposed expert witness, would be admitted into evidence. As we discuss infra, the District Court properly excluded Dr. Got-theimer from testifying under Fed.R.Evid. 702.
As we have mentioned, at the conclusion of a ten-day bench trial, the District Court entered judgment for Unisys and issued extensive findings of fact and conclusions of law. We review the District Court’s findings of facts for clear error. Application of legal precepts to historical facts receives plenary review. Feder v. Evans-Feder, 63 F.3d 217, 222 n. 9 (3d Cir.1995). The District Court’s decision to qualify an expert is reviewed for abuse of discretion. General Elec. Co. v. Joiner, 522 U.S. 136, 118 S.Ct. 512, 139 L.Ed.2d 508 (1997); In re Paoli R.R. Yard Litig., 35 F.3d 717, 741-46 (3d Cir.1994) (“Paoli II ”).
II.
Meinhardt participated in a 401(k) savings plan (“Plan”)5 administered by Uni-sys. Two companies, Sperry and Burroughs, had merged in 1986 to create Unisys, and thus their retirement plans also merged. See Unisys I, 74 F.3d at 425-26. Meinhardt and the class he represents elected to , invest their money in two of the funds offered by the Plan, the Fixed Income Fund (“FIF ”) and the Insurance Contract Fund (“ICF ”). Investments in the FIF/ICF were exclusively restricted to Guaranteed Investment Contracts (“GICs”).6 For ease of reference [150]*150throughout this Opinion we will refer to the FIF/ICF as the “Fund.”
Unisys described the Fund as one of the more conservative funds that was intended to return principal with interest.7 Plan participants could invest as much or as little of their money as they desired. In order to prevent interest rate arbitrage by the participants and in order to receive a higher yield from the GICs, Fund assets could not be transferred to the money market fund directly; Fund assets had to be held for at least a year in one of the four equity stock funds. In 1990, Unisys shortened this “equity wash” to a period of six months after receiving approval from Executive Life.App. 1702.
In 1987 and 1988, Unisys purchased three Executive Life GICs as investments for the Fund. The Executive Life GICs themselves were comprised of assets that potentially had high rates of return, some of which were high yield bonds, or “junk bonds.” The junk bonds did not fare well in the late 1980’s markets. In 1991, California regulators seized Executive Life and temporarily froze all payments from the Executive Life GICs. By 1996, however, the Fund reimbursed the principal to Meinhardt and had paid some interest, but at a lower rate than had been guaranteed. FF ¶ 80.
Meinhardt accuses Unisys of breaching its fiduciary duties of prudence, diversification, and disclosure with respect to the Executive Life contracts that had been purchased for the Fund. ERISA prescribes that fiduciaries must adhere to a standard of prudence. ERISA requires that a fiduciary’s duty shall be discharged:
with the care, skill, prudence, and diligence under the circumstances then prevailing that a prudent man acting in a like capacity and familiar with such matters would use in the conduct of an enterprise with like character and with like aims;....
29 U.S.C. § 1104(a)(1)(B).
III.
To determine whether Unisys had satisfied the ERISA standard of prudence, the district court found the following facts from the evidence.
Unisys delegated the responsibility of investing for the Fund to David White and Leon Level. White and Level have educational and practical backgrounds in financial matters. FF ¶¶ 17-18; App. 643-45, 1136-37. At the direction of White and Level, Unisys purchased three Executive Life GICs as investments for the Fund through bidding processes in June 1987, December 1987 (both for the FIF), and January 1988 (for the ICF). Of the many GICs purchased for the Fund, only three were Executive Life GICs, constituting between 15 and 20 percent of the Fund’s assets. FF ¶¶ 14-15; App. 4450. Unisys, through White and Level, considered many firms through a process of competitive bidding, and Unisys heard in-person presentations from the insurance companies. FF ¶ 20; App. 523,1154.
Unisys presented evidence that for the first bid (June 1987), White and Level hired an experienced investment consultant, Murray Becker, who evaluated many different insurance firms.8 FF ¶20. In evaluating potential insurance companies from which to purchase GICs, Becker obtained information and ratings from Standard and Poor’s and A.M. Best, ratings services that evaluate the stability and potential profitability of various types of [151]*151companies including insurance companies. Both ratings services gave Executive Life their highest rating.9 Becker and others testified that the ratings services were quite thorough because they analyzed raw data and interviewed investment managers. App. 535. Becker testified that he and other professionals had a high confidence in the thoroughness of the ratings services, which led to their respective ratings. FF ¶ 21; App. 658-62, 702-03, 708-12, 1160-61. As detailed in the District Court’s findings of fact, Becker was very familiar with how the ratings services evaluated the GICs. Id.
Prior to the first bid, Unisys reviewed Becker’s bid specifications. FF ¶ 20 n. 2; App. 1267-68, 3659. White testified that he carefully considered the use of high yield bonds and knew the risks involved. The prevailing view in the investment world at that time was that high yield guaranteed insurance contracts were good risks. FF ¶ 27; App. 1038-39.
In addition to understanding the risks associated with Executive Life GICs, White chose Executive Life GICs for their other unique features. He selected the three Executive Life GICs to balance other Fund investments — the Executive Life GICs had longer maturity dates, App. 656— 57, 692, and their portfolios lacked real estate mortgages or derivatives and had a low proportion of commercial real estate investments. App. 1010, 1156-58. Furthermore, Executive Life used the “barbell" approach in making investments for the GICs; that is, the higher risk associated with the high yield bonds was balanced with low risk, lower yield government bills. FF ¶ 25; App. 1156-58.
For the second two bids and upon completion of the merger between Burroughs and Sperry into Unisys, Unisys decided not to utilize Becker’s services. White, Level, and three other employees under their direction had sufficient professional experience to select GIC issuers. Moreover, Becker had charged the Plan $25,000 per bid. FF f 31; App. 1162-65. White and Level expanded the list of potential bidders for the second and third bids and maximized the market information available to them. FF ¶ 32; App. 1054-55.
In the months between the bids, White and Level “engaged in an ongoing process of reviewing and updating the information on the potential bidders.” FF ¶ 33; App. 615-22. They testified that they also kept abreast of developments in the GIC industry by reading trade publications and journals. FF ¶ 33 n. 6; App. 617, 632. They analyzed the portfolio and risk of the insurance carriers, using the Standard and Poor’s and A.M. Best ratings as a source of information about both the insurance companies’ asset composition and their creditworthiness. FF ¶ 35; App. 1056. They testified that they would not have been able to replicate the analyses done by the ratings services inhouse. App. 711. They had available to them SEC forms 10K and 10Q to review prior to making them selection. FF ¶ 35; App. 1065-66, 631. They had also consulted with a firm that Unisys had engaged to advise it on its defined benefit pension plan. That firm advised Unisys on its selection of issuers for the GIC funds. App. 608, 626-27.
In Unisys I, 74 F.3d at 436, we directed the District Court to determine whether the ratings could be used reliably by Uni-sys. As mentioned earlier, Level and White both testified that the ratings services were respected for their competence and thoroughness throughout the investment and finance community. App. 1160— 61, 658-623, 702, 708-11. The District Court found that the ratings services pro[152]*152vided reliable information. FF ¶ 21. We are satisfied that this finding is not clearly erroneous. See also Bussian v. RJR Nabisco, 21 F.Supp.2d 680, 686-87 (S.D.Tx. 1998) (“Nabisco’s use of the consultant and rating agencies [in selecting an Executive Life annuity] does not demonstrate imprudence.”).
The District Court also resolved at trial four other issues of fact that we identified in Unisys I. First, evidence in the summary judgment record may have indicated that Becker had recommended the purchase of a three-year GIC, rather than a five-year GIC. Unisys I, 74 F.3d at 427. At trial, however, Becker testified that he had not recommended the shorter maturity (three-year) Executive Life GIC. Rather, his discussion with Unisys officers about maturity dates was very general, leading to the conclusion that the investment in five-year GICs was appropriate. FF ¶ 30; App. 555-558.
Second, at the summary judgment stage, the evidence suggested that Becker told White that Executive Life would lose its AAA rating from Standard & Poor if its investments of junk bonds exceeded 35%, and White believed that 40-50% of Executive Life’s investments were junk bonds. Unisys I, 74 F.3d at 427. At trial, Becker stated that it was not his view that Executive Life would lose their Standard and Poor’s AAA rating if high yield bonds comprised more than 35% of Executive Life’s portfolio. Rather, he testified that Executive Life thought its AAA rating might be in jeopardy if their high yield bond holdings exceeded 35%. However, Standard and Poor’s had access to the actual percentage of high yield bonds in Executive Life’s portfolio, and it still issued a AAA rating to Executive Life. Thus, White’s reliance on the AAA rating was neither unreasonable nor imprudent. As discussed infra, even if White had an erroneous view of the percentage of high yield bonds in Executive Life’s portfolio, a hypothetical prudent fiduciary would have known that Executive Life’s high yield bond percentage was within an acceptable range in Executive Life’s and Standard and Poor’s analyses. FF ¶ 28; App 501.10
Third, in Unisys I, we stated:
[A] reasonable factfinder could infer from this evidence that Unisys failed to analyze the bases underlying [Becker’s] opinion of Executive Life’s financial condition and to determine for itself whether credible data supported [Becker’s] recommendation that Unisys consider investing plan assets with the insurer.
' A reasonable factfinder could also con-, elude that Unisys passively accepted its consultant’s positive appraisal of Executive Life without conducting the independent investigation that ERISA requires.
Unisys I, 74 F.3d at 435-36 (emphasis added). However, after taking evidence at trial, the District Court did not find that Unisys had failed to make its own evaluation of Executive Life’s financial condition, nor did it find that Unisys “passively” had accepted Becker’s appraisal. On the contrary, the District Court made numerous findings that White and Level were aware of the composition of assets of Executive Life GICs and that they understood the risks associated with each of those assets. FF PP 25-27.
Fourth, in Unisys I, we advised the District Court that it should determine the significance, if any, of Executive Life’s substantially higher interest rates. We suggested that dramatically higher interest rates might have prompted Unisys to conduct extra investigation into Executive Life’s creditworthiness. As stated earlier, at trial, White testified that he carefully had considered the use of high yield bonds and knew the risks involved. Unisys recognized that higher rates could, over time, yield dramatic differences in income, but [153]*153that the trustees were “constrained by their standards of risk tolerance.” FF ¶ 25; App. 1250. The District Court credited the testimony of the Unisys fiduciaries and was satisfied and concluded that Uni-sys had made a reasonable and thorough investigation of Executive Life GICs. CL ¶ 3. We will not disturb that holding here.11
IV.
The District Court’s factual findings support its legal conclusions that Unisys was prudent under the standard articulated in ERISA and that a hypothetical prudent investor would have purchased each of the three GICs. As we stated in Unisys I, ERISA requires that a fiduciary shall discharge his duties
with the care, skill, prudence, and diligence under the circumstances then prevailing that a prudent man acting in a like capacity and familiar with such matters would use in the conduct of an enterprise with like character and with like aims;....
Unisys I, 74 F.3d at 434 (quoting 29 U.S.C. § 1104(a)(1)(B)). We also stated that the prudence requirement focuses on “a fiduciary’s conduct in arriving at an investment decision, not on its results, and asking whether a fiduciary employed the appropriate methods to investigate and determine the merits of a particular investment.” Id.
After taking evidence on the issue of Unisys’s prudence, the District Court held that the actions taken by the Fund’s trustees satisfied the prudence standard: “Based on the evidence at trial I find that the Unisys fiduciaries undertook adequate and reasonable steps before purchasing the three Executive Life contracts.” CL ¶ 3. The District Court concluded, “Measured by any standard, the Unisys fiduciaries’ actions are consistent with the prudence requirements of ERISA.” CL ¶ 13. We hold that the District Court’s findings of fact support its conclusions of law that Unisys was prudent in investing in Executive Life GICs, and thus Meinhardt failed to prove an essential element of his ERISA claim.
As an alternate theory for holding that Unisys was not imprudent, the District Court considered the objective prudence of Unisys investments in Executive Life GICs by applying the “hypothetical prudent investor” test. Unisys I, 74 F.3d at 436 (citing Fink v. National Savings & Trust Co., 772 F.2d 951, 962 (D.C.Cir.1986) (Scalia, J., concurring in part and dissenting in part) and Roth v. Sawyer-Cleator Lumber Co., 16 F.3d 915, 919 (8th Cir.1994)).
The District Court held that a hypothetical prudent fiduciary would have invested in Executive Life GICs because (1) Executive Life was qualified under federal regu[154]*154lations as an insurance company authorized to provide annuities to facilitate the termination of benefit pension plans because it was state licensed, 46 Fed.Reg. 9532, 9534 (1981); (2) other judicial decisions endorsed the purchase of Executive Life annuities, e.g., Riley v. Murdock, 890 F.Supp. 444, 458-60 (E.D.N.C.1995);12 (3) Becker, the adviser Unisys retained for the first bid, included Executive Life on his approved list of GIC bidders until six months after Unisys made its third and final purchase of Executive Life, App. 559; and (4) other well-known pension plans purchased Executive Life GICs.App. 559, 1742. The District Court did not err in concluding that a hypothetical prudent fiduciary would have made the same investments in Executive Life GICs as the investments made by Unisys. FF ¶ 24 n. 3; CL ¶¶ 8-10.
In sum, we are satisfied that the District Court’s holdings that Unisys was prudent, and in the alternative, that a hypothetical prudent fiduciary would have made the same investments, are supported by the evidence.
V.
In addition to holding that the trustees’ actions satisfied the standard of prudence required by ERISA, the District Court went on to discuss why the trustees’ actions were not arbitrary and capricious. The District Court need not have discussed application of an arbitrary and capricious standard in this case. In light of the District Court’s holding of prudence and our affirmance of that holding, the District Court’s discussion of an arbitrary and capricious standard cannot affect the judgment in favor of Unisys.
In Unisys I, we stated that fiduciaries of investment plans had to satisfy the “prudent” legal standard specified in ERISA, cited supra. We stated that one of ERISA’s underlying purposes was “to enforce strict fiduciary standards.” Unisys I, 74 F.3d at 434 (citing 29 U.S.C. § 1001 and H.R.Rep. No. 93-533 (1974), reprinted in 1974 U.S.C.C.A.N. 4639, 4639-43).
In Struble v. New Jersey Breioery Employees’ Welfare Trust Fund, 732 F.2d 325 (3d Cir.1984), we held specifically that the duties of loyalty and prudence demanded by ERISA should not be reviewed through an “arbitrary and capricious” lens. We held that the “standards set forth explicitly in ERISA” should be used to evaluate the trustees’ conduct. Id. at 333-34 (finding support in cases from the Second, Fifth, and Eleventh Circuits). Struble governs the question of Unisys’s duty of prudence under ERISA.
The District Court should have applied only the standard of “prudence under the circumstances” as required by the statute. Only the standard found in ERISA, 29 U.S.C. § 1104(a)(1)(B); Unisys I, 74 F.3d at 434, should have been applied to determine whether Unisys’s investment methods were prudent.
As authority for an arbitrary and capricious standard, the District Court cited Varity Corp. v. Howe, 516 U.S. 489, 116 S.Ct. 1065, 134 L.Ed.2d 130 (1996), Firestone Tire & Rubber Co. v. Bruch, 489 U.S. 101, 109 S.Ct. 948, 103 L.Ed.2d 80 (1989), and Moench v. Robertson, 62 F.3d 553 (3d Cir.1995), cert. denied, 516 U.S. 1115, 116 S.Ct. 917, 133 L.Ed.2d 847 (1996). These cases, however, involved situations not relevant to the present claims asserted against Unisys.
In the context of a case challenging a denial of benefits under 29 U.S.C. § 1132(a)(1)(B) — and not challenging the prudence of investment decisions — the Supreme Court held that the “inherently discretionary” nature of fiduciary functions does not necessarily require a deferential standard of review. Firestone Tire & Rubber Co. v. Bruch, 489 U.S. 101, 112, [155]*155109 S.Ct. 948, 103 L.Ed.2d 80 (1989). Under ERISA, the standard of review over a trustee’s decision to deny benefits or the interpretation of the plan is de novo as a general rule; only when the plan gives the trustee discretion to deny benefits or construe the terms of the plan should a court employ the arbitrary and capricious standard. As the instant case does not concern a denial of benefits under 29 U.S.C. § 1132(a)(1)(B) or an interpretation of Un-isys’s Plan, Firestone’s standard is inapplicable. Nor did Varity Corp. v. Howe, 516 U.S. 489, 116 S.Ct. 1065, 134 L.Ed.2d 130 (1996), involve a claim that a trustee’s investments were imprudent — the claim that Meinhardt makes here.
In Moench v. Robertson, 62 F.3d 553 (3d Cir.1995), cert. denied, 516 U.S. 1115, 116 S.Ct. 917, 133 L.Ed.2d 847 (1996), we did apply a deferent arbitrary and capricious standard of review to a claim by a plan’s participants that the fiduciary was imprudent. We were careful to point out in Moench, however, that our holding was limited to the specific type of plan involved in that case, an Employee Stock Ownership Plan (“ESOP”). Here, of course, the Unisys Plan was not an Employee Stock Ownership Plan. ' Furthermore, Moench specifically held its analysis was in “complete harmony with the prudent man standard of care obligations imposed by 29 U.S.C. § 1104 on fiduciaries, as our holding implicates only the standard of review of the conduct of a fiduciary and not the standards governing that conduct,” Moench, 62 F.3d at 566 n. 3 (emphasis added), as is the case here.
In sum, Unisys’s methods of making that decision must be evaluated using the ERISA standard mandated by Unisys I and in accordance with Struble. The District Court did not err in concluding that Unisys did not breach its duty of prudence.
For these reasons, the District Court’s discussion of an arbitrary and capricious standard was superfluous and constitutes no more than harmless error. Fed. R.Civ.P. 61. The District Court’s statements that Unisys’s actions were not arbitrary and capricious do not negate its otherwise correct holding that Unisys satisfied the ERISA prudence standard.
VI
Meinhardt also argues that the District Court abused its discretion when it decided to exclude the testimony of Dr. George M. Gottheimer, one of Meinhardt’s two proposed expert witnesses.13 Meinhardt offered Dr. Gottheimer ■ to testify on the subject of “the customary methods of investigating the financial condition and creditworthiness of insurance companies.”
To qualify as an expert under Fed.R.Evid. 702, a witness must have sufficient qualifications in the form of knowledge, skills, and training. Additionally, the court must find that the testimony of the expert will be reliable and that the testimony will “fit,” that is, assist the trier of fact. In re Paoli R.R. Yard Litig., 35 F.3d 717, 741-43 (3d Cir.1994). While it may be arguable that the “fit” prescribed in In re Paoli is a “fit” reflecting on the substance of the witness’ testimony, we think it just as relevant to the “fit” reflecting on the witness’ credibility. Indeed, in the recent Supreme Court decision discussing the standard of review applicable to the admission and exclusion of expert evidence, the Supreme Court refers to the District Court’s “gatekeeper” role of screening such evidence to ensure that it is not only relevant but reliable. The Court goes on to write, “A court of appeals applying ‘abuse of discretion’ review to [expert testimony] rulings may not categori[156]*156cally distinguish between rulings allowing expert testimony and rulings which disallow it.” General Elec. Co. v. Joiner, 522 U.S. 136, 118 S.Ct. 512, 517, 139 L.Ed.2d 508 (1997). Thus in our view, the Court’s emphasis on reliability as well as on relevancy embraces within its standard the credibility of the witness proffering expert opinion. This is particularly true where, as here, it is the district court judge sitting as a finder of fact who must rule on issues of evidence. See Goodman v. Highlands Ins. Co., 607 F.2d 665, 668 (5th Cir.1979) (“[A] trial judge sitting without a jury is entitled to even greater latitude concerning the admission or exclusion of evidence.”).
While we could understand issue being taken with the Goodman precept, it appears to us after Joiner that the Goodman standard has been given increased viability. Although Joiner was a summary ■judgment decision, it nevertheless emphasized that Daubert did not alter the general rule announced in Spring Co. v. Edgar, 99 U.S. 645, 25 L.Ed. 487 (1878). In Edgar, the Court stated, “ ‘cases arise where it is very much a matter of discretion with the court whether to receive or exclude the evidence; but the appellate court will not reverse in such a case, unless the ruling is manifestly erroneous.’ ” Joiner, 118 S.Ct. at 517 (quoting Edgar, 99 U.S. at 658). After so stating, the Court rejected any alteration of this rule and in the context of expert testimony said, “But Daubert \v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993) ] did not address the standard of appellate review for evidentiary rulings at all” Id. The Court then repeated that under Daubert “ ‘the trial judge must ensure that any and all scientific testimony or evidence admitted is not only relevant, but reliable.’ ” Id. (quoting Daubert, 509 U.S. at 589, 113 S.Ct. 2786).
The Court went on to hold in Joiner that the Eleventh Circuit had erred in reviewing the exclusion of Joiner’s experts’ testimony because it failed to give the trial court the deference that is the hallmark of abuse of discretion review. Id. (citing Koon v. United States, 518 U.S. 81, 97-99, 116 S.Ct. 2035, 135 L.Ed.2d 392 (1996)). The Court further held that the studies upon which Joiner’s experts relied were not sufficient whether individually or in combination, to support their conclusions that Joiner’s exposure to PCBs contributed to Joiner’s cancer, and that the District Court therefore did not abuse its discretion in excluding their testimony.14
In the instant case, the District Court ruled that Dr. Gottheimer’s testimony would not be admissible for three reasons. First, the court found that Dr. Gottheimer’s educational credentials were not of the highest caliber.15 Second, during Dr. Got-theimer’s voir dire, the District Court found -Dr. Gottheimer not to be credible because he had made statements about his credentials that were inconsistent with his deposition testimony. Finally, the District Court found that Dr. Gottheimer’s expertise was in property casualty insurance, not life insurance, and that Gottheimer had admitted in his deposition that there are “fundamental” differences in evaluating the two types of insurance. FF ¶¶ 101-05; CL ¶¶ 17-19.
These three reasons coincide with the three requirements articulated in Paoli II: qualifications, reliability, and fit. The record discloses that Dr. Gottheimer’s qualifications were less than stellar. Because he had testified untruthfully at voir dire, his testimony could well have been held unreliable. Finally, Dr. Gottheimer’s alleged expertise, limited in any event to methods of investing with respect to property casu[157]*157alty insurance, did not fit with or meet the need of the District Court for expert testimony in life insurance investing. See Surace v. Caterpillar, Inc., 111 F.3d 1039, 1055-56 (3d Cir.1997). The District Court determined that Dr. Gottheimer could not be a credible witness based on admissions secured through the use of his prior sworn testimony. See FF ¶¶ 102-104. Because the District Court, as fact-finder, listened to the testimony and assessed the credibility of the witness, these findings are entitled to great deference by this Court. See Anderson v. City of Bessemer City, N.C., 470 U.S. 564, 105 S.Ct. 1504, 84 L.Ed.2d 518 (1985).
Judge Becker, in his thoughtful and comprehensive dissent, while focusing almost exclusively on the standards for admissibility of scientific expert testimony, nevertheless acknowledges that “the fact-finder is ordinarily the arbiter of general credibility,” Dissent at 167, and that “the power to evaluate the credibility of witnesses and give testimony its proper weight primarily resides with the trier of fact.” Dissent at 167. He also properly acknowledges that the decision to admit or to exclude expert testimony is reviewed for abuse of discretion.
Judge Becker, however, fails to recognize or credit in his dissent two significant and controlling issues. First, Dr. Got-theimer’s testimony does not fall within the scope of scientific testimony, and accordingly, it should not be tested by the particular standards required for testimony based on a particular scientific ethic.16 See Carmichael v. Samyang Tire, Inc., 131 F.3d 1433 (11th Cir.1997), cert. granted sub nom. Kumho Tire Co. v. Carmichael, — U.S. -, 118 S.Ct. 2339, 141 L.Ed.2d 711 (1998). It is true of course that we have referred to the Paoli requirements of qualifications, reliability and fit — but we have done so only to emphasize that, measured by any standard, scientific or nonscientific, the District Court did not abuse its discretion in excluding Dr. Gottheimer’s testimony.
Second, and more important, the dissent, while acknowledging that it is the fact finder that determines weight and credibility of an expert’s testimony, apparently overlooks the distinguishing circumstance here: the fact finder was the District Court judge himself, and not a jury. Judge Hutton made the critical credibility determination that he could not believe the testimony of Dr. Gottheimer, and that being so, no reason has been put forward as to why we should not credit and defer to the District Court’s finding. Even if we might have made a different determination regarding Dr. Gottheimer’s credibility, we are not at liberty to impose our opinion on the District Court.17
We would be hard pressed to require a District Court judge sitting in a non-jury case who credibly and with reason found that he could not believe a witness to nevertheless hear the witness’s direct examination, cross-examination, and rebuttal examination in an extended trial when he knew that he would only reject it as unbelievable. All the instances and cases cited by the dissent, see, e.g., Dissent at 162 n. 1, 170 n. 13, are those in which it was for the jury as fact finder to determine credibility and weight of the expert testimony. Thus, [158]*158those cases are wholly inapplicable to the facts of this case. When the role of the gatekeeper to admit or exclude evidence (the judge) and the role of the factfinder to assess and weigh the evidence that was admitted (the jury) are one and the same, the judge who becomes the factfinder as well as the gatekeeper must be given great deference by this Court, and, as we note below, should not be required to waste judicial time. See Fed.R.Evid. 403. Therefore, we cannot say on this record that it was an abuse of the District Court’s discretion to exclude Dr. Gottheimer’s testimony.
Even if the District Court had abused its discretion, and we hold that it did not, the error must be deemed harmless in light of the District Court’s finding that Dr. Gottheimer was not credible. The District Court concluded, “If given the chance to testify, I could not find [Dr. Gottheimer] to be a credible witness given his evasiveness, if not his propensity to state falsehoods.” CL ¶ 18. Obviously, hearing testimony from a witness who was given no credence at all by the District Court judge presiding at a bench trial would have resulted in the “waste of time” proscribed by Federal Rule of Evidence 403, particularly where the false statements identified by the judge were material to the purported expert’s qualifications.
VII.
ERISA requires a fiduciary to “diversifyf ] the investments of the plan so as to minimize the risk of large losses, unless under the circumstances it is clearly not ■prudent to do so.” 29 U.S.C. § 1104(a)(1)(C). Meinhardt complains that Unisys invested an excessive amount of Fund investments in Executive Life GICs. As discussed in Unisys I, Congress did not try to quantify diversity with percentages, leaving that determination to the facts and circumstances as found by the courts. Unisys I, 74 F.3d at 438-40.
The District Court determined that Me-inhardt had not introduced evidence by way of expert testimony as to what would have constituted a properly diversified fund. At the time Executive Life went into receivership, the Fund had 20% of its assets in Executive Life investments, and the court held this level of diversification to be proper.18 CL ¶¶ 32-33.
Nor did Meinhardt prove his ease with respect to the duty to diversity because he did not show that the Fund suffered “large losses” as a result of any failure to diversify. This was an issue that the Court of Appeals specifically held was not known at the summary judgment stage. See Unisys I, 74 F.3d at 440. Meinhardt presented no evidence of investments that would have constituted proper diversification in order to prove that Unisys did not properly diversify the investments in the Fund or to enable the District Court to assess losses, if any, to Meinhardt for the difference. FF ¶ 90.
The duty to diversify and resulting damages from a breach of that duty could not be determined from the summary judgment record in Unisys I. Now that the trial has concluded, it is evident to us, as it was to the District Court, that Meinhardt’s failure of proof did not lead to any determination that Unisys breached its duty to diversify or that damages resulted.
VIII.
Meinhardt claims that Unisys did not fulfill its obligation of making necessary disclosures under ERISA.
In Unisys I, we stated that “a fiduciary may not materially mislead those to which section 1104(a)’s duties of loyalty and prudence are owed.” Unisys I, 74 F.3d at 440-41. A fiduciary must make [159]*159disclosures if silence would be harmful. Bixler v. Central Pa. Teamsters Health & Welfare Fund, 12 F.3d 1292, 1300 (3d Cir.1993). ERISA also requires plaintiffs to prove losses for any breach of fiduciary duty claim:
Any person who is a fiduciary with respect to a plan who breaches any of the responsibilities, obligations, or duties imposed upon fiduciaries by this subchap-ter shall be personally liable to make good to such plan any losses to the plan resulting from each such breach.
29 U.S.C. § 1109(a) (emphasis added). As Meinhardt and the other class plaintiffs were seeking individual relief under 29 U.S.C. § 1132(a)(3) (in contrast to § 1132(a)(2), which only allows relief on behalf of the Plan), Meinhardt was required to prove individual losses. Varity Corp. v. Howe, 516 U.S. 489, 507-15, 116 S.Ct. 1065,134 L.Ed.2d 130 (1996).
Although the District Court’s discussion of Meinhardt’s claims that Unisys breached its duty to disclose information about Executive Life spans 18 pages, we can dispose of this issue on appeal briefly. Essentially, Meinhardt complains that Uni-sys received reports about Executive Life’s financial troubles in early 1990. Meinhardt claims that Unisys (1) did not warn the Fund participants, (2) drafted misleading letters in order to dispel participants’ concern, (3) did not disclose the fact that a high-level Unisys executive had purged his own portfolio of Executive Life securities, and (4) entered into an agreement with Executive Life not to disclose information to participants that would cause participants to change their investments.19 The District Court held that Me-inhardt did not prove that the alleged failures to disclose were material. CL ¶¶ 22-23.
We need not address the question of whether the alleged nondisclosures were material, however, because it is clear that Meinhardt did not prove that any alleged failures to disclose caused the participants to suffer damages. CL ¶¶ 29-30. The District Court found that Meinhardt and the other class plaintiffs (1) already had actual knowledge of much of the information it is claimed that Unisys failed to disclose, (2) did not read the Plan documents, and (3) testified that they would not have withdrawn or transferred their money from the Fund even if they had known about Executive Life’s problems. FF ¶¶ 70-71; CL ¶ 28; App. 1681-82, 1688-89.
Moreover, Meinhardt’s expert, Tsetse-kos, offered testimony on losses suffered as a result of the alleged failures to disclose, but referred only to those losses incurred by the Fund and not to any losses incurred by individual participants named as plaintiffs. FF ¶¶ 76-77; CL ¶¶ 29-31. Meinhardt also failed to prove individual damages suffered by each participant as ERISA requires. 29 U.S.C. § 1132(a)(3).
We hold that these factual findings of the District Court are not clearly erroneous and that they support the conclusion reached by the District Court that Mein-hardt failed to prove his claim that Unisys breached its duty of disclosure.
IX.
A final word should be said about Mein-hardt’s claim for damages. First and foremost, in the absence of proof of a breach of fiduciary duty, no relief in the way of damages or losses could accrue to Mein-hardt. We have held that Unisys satisfied ERISA’s prudence standard and that accordingly, no breach of fiduciary duty occurred. This being so, no claim for increased interest, ie., the promised interest minus the actual amount of interest received, or any other damages, can be sustained. As we have noted earlier, Mein-hardt had received the return of the entire [160]*160principal invested as well as some interest.20
It is therefore irrelevant as to whether any losses sustained by the Fund from GIC investments could have been offset by any gains derived from other Fund investments. While we acknowledge that a trustee, when he is imprudent and breaches his trust, is liable for all gains and may not offset losses against them,21 in the instant case, the Unisys fiduciaries were neither imprudent nor did they breach their fiduciary duties.22
Additionally, Meinhardt and the Department of Labor as amicus also argued that the burden of proving causation of damages shifts to the defendant after the plaintiff has proved that the defendant breached a fiduciary duty. Here, the District Court assigned the burden of proof to the plaintiff Meinhardt. Because we have held that Unisys did not breach its fiduciary duties, we have no need to address the issue of which party bears the burden of proving causation of damages resulting from a breach of fiduciary duty. While we recognize that our sister circuits have divided in deciding this question,23 we have yet to express ourselves on this issue.24
X.
In sum, we have held that:
(1)The District Court’s findings of fact issued after hearing evidence on Me-inhardt’s ERISA claims will be affirmed as not clearly erroneous.
(2) The District Court’s conclusions of law that the Unisys fiduciaries were prudent, and in the alternative, that a hypothetical prudent fiduciary would have made the same investments in Executive Life GICs, also will be affirmed.
(3) Although we do not agree with the District Court’s additional discussion of an arbitrary and capricious standard in reviewing the investments made by the ERISA fiduciaries, this discussion was superfluous, constitutes no more than harmless error, and does not affect our judgment.
(4) The District Court did not abuse its discretion in excluding the testimony of Meinhardt’s proposed expert witness on the issue of Unisys’s prudence, and in any event, that action was harmless in light of the District Court’s finding that the expert was not credible.
(5) The District Court did not err in denying relief to Meinhardt inasmuch as no losses or damages could be sustained. As a consequence, we have found it unnecessary to address the disputed issue of which party bears the burden of proving causation of damages that result from a breach of fiduciary duty.
[161]*161(6) The District Court did not err in holding that Meinhardt’s other ERISA claims, failure to diversify and failure to disclose information, were not proved.
Thus, we will affirm the District Court’s orders of November 24, 1997, and January 9, 1998, in favor of Unisys and against Meinhardt.
Each party shall bear its own costs.