MEMORANDUM AND ORDER
JOHN W. LUNGSTRUM UNITED STATES DISTRICT JUDGE
These related actions come before the Court on plaintiff’s Motion in Limine to Admit Expert Statistical Sampling Testimony, which plaintiff has filed in each case. For the reasons set forth below, the motion is granted to the extent set out herein.
Plaintiff National Credit Union Administration Board brings these suits as conservator and liquidating agent of various credit unions. The suits relate to a number of offerings involving different residential mortgage-backed securities (“RMBS” or “certificates”) purchased by the credit unions. Plaintiff asserts claims under federal and state law against sellers, underwriters, and issuers for the certificates, based on alleged untrue statements or omissions of material facts relating to each certificate.
On July 23, 2013, plaintiff filed the present motion in four of the remaining suits. Defendants in those suits filed a joint response brief on August 20, 2013, and plaintiff filed a consolidated reply brief on September 3, 2013. Since that time, the parties have filed and responded to various notices of supplemental authority. On March 17, 2013, plaintiff orally made the same motion in Case No. 13-2418-JWL (which case was initiated after the filing of the motion in the other cases), by which it incorporated its prior briefs.
By its motion, plaintiff seeks “a ruling approving the use of statistical sampling and for the admission of testimony by [plaintiff’s] sampling expert, Dr. Charles D. Cowan, ” on the basis that Dr. Cowan’s opinions, as set forth in a written report dated July 23, 2013, comply with the standards for expert testimony imposed by Fed.R.Evid. 702 and the Daubert line of cases. Dr. Cowan’s report sets out a method by which he proposes to select loan files for statistical sampling. Under that method, Dr. Cowan would randomly select 25 loans for each of four strata, differentiated by the borrowers’ FICO credit scores for the loans, for a total of 100 loans within each Supporting Loan Group (“SLG”) that backed the certificates at issue in these cases. Dr. Cowan would also randomly select 25 backup loans for each stratum within each SLG that would be used in random order if any of the original 25 loan files were missing. Dr. Cowan would then test the samples, using 11 variables, to ensure that they were sufficiently representative of the larger populations of loans. The sample loans would then be re-underwritten (by other persons), and Dr. Cowan would then extrapolate the results of the re-underwriting of the samples to the larger populations. Dr. Cowan offered the opinions that such a method of statistical sampling is scientifically valid and that his sample sizes, which would yield a confidence level of 95 percent with a margin of error of 10 percent, are sufficient.
A. Timing of Ruling
1. Defendants argue that the Court should not entertain plaintiff’s motion for a Daubert ruling at this time. Defendants first argue that because Dr. Cowan’s report envisions further steps to be taken and the issuance of future opinions, a Daubert ruling at this time is precluded by Fed.R.Evid. 702 and Fed.R.Civ.P. 26. The Court rejects this argument.
Defendants rely on Rule 702’s statement that an expert may testify in the form of an opinion if, among other things, “the expert has reliably applied the principles and methods to the facts of the case.” See Fed.R.Evid. 702(d). Defendants argue that Dr. Cowan has merely proposed using a certain method and has not yet “applied” his method in this case, as he has not yet chosen the sample loans, tested those samples, or extrapolated any results. By the time Dr. Cowan testifies at trial, however, he will have completed the application of his sampling method to the particular loans at issue in this case. Dr. Cowan’s further opinions, after application of his method, must be disclosed, and defendants will then have the opportunity to seek exclusion of those opinions under Rule 702. That rule, on its face, does not prohibit either the issuance of multiple expert reports by a single expert working in stages or the consideration of a Court of one prong of Rule 702 (for instance, reliability) at a time. Nor have defendants cited any authority interpreting Rule 702 as they do.
Defendants also rely on Rule 26(a)(2)’s requirement of an expert report that contains “a complete statement of all opinions the witness will express and the basis and reasons for them.” See Fed.R.Civ.P. 26(a)(2)(B)(i). Again, however, the cited rule does not prohibit an expert from issuing multiple reports disclosing discrete opinions, and defendants have failed to cite caselaw supporting such an interpretation. Indeed, experts commonly issue multiple reports in a single case; for instance, a medical expert may issue a separate report for each of multiple plaintiffs that have brought an action. The Court concludes that neither Rule 702 nor Rule 26 precludes the Court’s ruling on plaintiff’s motion at this time.
2. Defendants also argue that plaintiff’s motion is premature because fact discovery has not yet been completed. Defendants argue specifically that the Court cannot determine whether Dr. Cowan’s testimony will be helpful to the jury, see Fed.R.Evid. 702(a), until all of the facts of the case are known. The Court need not decide at this time, however, whether these particular opinions will ultimately be helpful. These opinions by Dr. Cowan provide the foundation for future opinions by him and others. The experts’ ultimate conclusions may then be tested for helpfulness as required by Rule 702. Thus, if discovery reveals that some aspect of Dr. Cowan’s testimony will not be helpful for some reason, defendants will be free to seek to exclude that testimony before trial. See Allstate Ins. Co. v. Countrywide Fin. Corp., 2013 WL 6231713, at *16 (C.D. Cal. Dec. 2, 2013) (Pfaelzer, J.) (Court cannot determine whether results of sampling will be helpful until the final results are known).
Defendants also assert that Dr. Cowan’s sampling method cannot yet be shown to be reliable at this stage, for four reasons.
a. First, defendants argue that because Dr. Cowan has not specifically identified and applied the specific method of random selection of the loans, there can be no guarantee that he will in fact implement his method as designed and intended. Dr. Cowan’s present opinion, however, is that his proposed method is valid. Dr. Cowan’s implementation of his method must be set forth in a future report, and if his implementation is improper or unreliable, defendants may challenge that ...