opinion: BOURJAILY v. UNITED STATES
  No. 85-6725.
  Argued April 1, 1987
  Decided June 23, 1987
  Rehnquist, C. J., delivered the opinion of the Court, in which White, Powell, Stevens, O’Connor, and Scalia, JJ., joined. Stevens, J., filed a concurring opinion, post, p. 184. Blackmun, J., filed a dissenting opinion, in which Brennan and Marshall, JJ., joined, post, p. 186.
  Stephen Allan Saltzburg argued the cause for petitioner. With him on the briefs were James R. Willis and James M. Shellow.
  Lawrence S. Robbins argued the cause for the United States. With him on the brief were Solicitor General Fried, Assistant Attorney General Weld, and Deputy Solicitor General Bryson.
  Judy Clarke and Mario G. Conte filed a brief for the National Association of Criminal Defense Lawyers as amicus curiae urging reversal.
  Chief Justice Rehnquist
  delivered the opinion of the Court.
  Federal Rule of Evidence 801(d)(2)(E) provides: “A statement is not hearsay if. . . [t]he statement is offered against a party and is ... a statement by a coconspirator of a party during the course and in furtherance of the conspiracy.” We granted certiorari to answer three questions regarding the admission of statements under Rule 801(d)(2)(E): (1) whether the court must determine by independent evidence that the conspiracy existed and that the defendant and the declarant were members of this conspiracy; (2) the quantum of proof on which such determinations must be based; and (3) whether a court must in each case examine the circumstances of such a statement to determine its reliability. 479 U. S. 881 (1986).
  In May 1984, Clarence Greathouse, an informant working for the Federal Bureau of Investigation (FBI), arranged to sell a kilogram of cocaine to Angelo Lonardo. Lonardo agreed that he would find individuals to distribute the drug. When the sale became imminent, Lonardo stated in a tape-recorded telephone conversation that he had a “gentleman friend” who had some questions to ask about the cocaine. In a subsequent telephone call, Greathouse spoke to the “friend” about the quality of the drug and the price. Greathouse then spoke again with Lonardo, and the two arranged the details of the purchase. They agreed that the sale would take place in a designated hotel parking lot, and Lonardo would transfer the drug from Greathouse’s car to the “friend,” who would be waiting in the parking lot in his own car. Greathouse proceeded with the transaction as planned, and FBI agents arrested Lonardo and petitioner immediately after Lonardo placed a kilogram of cocaine into petitioner’s car in the hotel parking lot. In petitioner’s car, the agents found over $20,000 in cash.
  Petitioner was charged with conspiring to distribute cocaine, in violation of 21 U. S. C. §846, and possession of cocaine with intent to distribute, a violation of 21 U. S. C. § 841(a)(1). The Government introduced, over petitioner’s objection, Angelo Lonardo’s telephone statements regarding the participation of the “friend” in the transaction. The District Court found that, considering the events in the parking lot and Lonardo’s statements over the telephone, the Government had established by a preponderance of the evidence that a conspiracy involving Lonardo and petitioner existed, and that Lonardo’s statements- over the -telephone had been made in the course of and in furtherance of the conspiracy. App. 66-75. Accordingly, the trial court held that Lonardo’s out-of-court statements satisfied Rule 801(d)(2)(E) and were not hearsay. Petitioner was convicted on both counts and sentenced to 15 years. The United States Court of Appeals for the Sixth Circuit affirmed. 781 F. 2d 539 (1986). The Court of Appeals agreed with the District Court’s analysis and conclusion that Lonardo’s out-of-court statements were admissible under the Federal Rules of Evidence. The court also rejected petitioner’s contention that because he could not cross-examine Lonardo, the admission of these statements violated his constitutional right to confront the witnesses against him. We affirm.
  Before admitting a co-conspirator’s statement over an objection that it does not qualify under Rule 801(d)(2)(E), a court must be satisfied that the statement actually falls within the definition of the Rule. There must be evidence that there was a conspiracy involving the declarant and the nonoffering party, and that the statement was made “during the course and in furtherance of the conspiracy.” Federal Rule of Evidence 104(a) provides: “Preliminary questions concerning . . . the admissibility of evidence shall be determined by the court.” Petitioner and the Government agree that the existence of a conspiracy and petitioner’s involvement in it are preliminary questions of fact that, under Rule 104, must be resolved by the court. The Federal Rules, however, nowhere define the standard of proof the court must observe in resolving these questions.
  We are therefore guided by our prior decisions regarding admissibility determinations that hinge on preliminary factual questions. We have traditionally required that these matters be established by a preponderance of proof. Evidence is placed before the jury when it satisfies the technical requirements of the evidentiary Rules, which embody certain legal and policy determinations. The inquiry made by a court concerned with these matters is not whether the proponent of the evidence wins or loses his case on the merits, but whether the evidentiary Rules have been satisfied. Thus, the evidentiary standard is unrelated to the burden of proof on the substantive issues, be it a criminal case, see In re Winship, 397 U. S. 358 (1970), or a civil case. See generally Colorado v. Connelly, 479 U. S. 157, 167-169 (1986). The preponderance standard ensures that before admitting evidence, the court will have found it more likely than not that the technical issues and policy concerns addressed by the Federal Rules of Evidence have been afforded due consideration. As in Lego v. Twomey, 404 U. S. 477, 488 (1972), we find “nothing to suggest that admissibility rulings have been unreliable or otherwise wanting in quality because not based on some higher standard.” We think that our previous decisions in this area resolve the matter. See, e. g., Colorado v. Connelly, supra (preliminary fact that custodial confessant waived rights must be proved by preponderance of the evidence); Nix v. Williams, 467 U. S. 431, 444, n. 5 (1984) (inevitable discovery of illegally seized evidence must be shown to have been more likely than not); United States v. Matlock, 415 U. S. 164 (1974) (voluntariness of consent to search must be shown by preponderance of the evidence); Lego v. Twomey, supra (voluntariness of confession must be demonstrated by a preponderance of the evidence). Therefore, we hold that when the preliminary facts relevant to Rule 801(d)(2)(E) are disputed, the offering party must prove them by a preponderance of the evidence.
  Even though petitioner agrees that the courts below applied the proper standard of proof with regard to the preliminary facts relevant to Rule 801(d)(2)(E), he nevertheless challenges the admission of Lonardo’s statements. Petitioner argues that in determining whether a conspiracy exists and whether the defendant was a member of it, the court must look only to independent evidence — that is, evidence other than the statements sought to be admitted. Petitioner relies on Glasser v. United States, 315 U. S. 60 (1942), in which this Court first mentioned the so-called “bootstrapping rule.” The relevant issue in Glasser was whether Glasser’s counsel, who also represented another defendant, faced such a conflict of interest that Glasser received ineffective assistance. Glasser contended that conflicting loyalties led his lawyer not to object to statements made by one of Glasser’s co-conspirators. The Government argued that any objection would have been fruitless because the statements were admissible. The Court rejected this proposition:
  “[S]uch declarations are admissible over the objection of an alleged co-conspirator, who was not present when they were made, only if there is proof aliunde that he is connected with the conspiracy. . . . Otherwise, hearsay would lift itself by its own bootstraps to the level of competent evidence.” Id., at 74-75.
  The Court revisited the bootstrapping rule in United States v. Nixon, 418 U. S. 683 (1974), where again, in passing, the Court stated: “Declarations by one defendant may also be admissible against other defendants upon a sufficient showing, by independent evidence, of a conspiracy among one or more other defendants and the declarant and if the declarations at issue were in furtherance of that conspiracy.” Id., at 701, and n. 14 (emphasis added) (footnote omitted). Read in the light most favorable to petitioner, Glasser could mean that a court should not consider hearsay statements at all in determining preliminary facts under Rule 801(d)(2)(E). Petitioner, of course, adopts this view of the bootstrapping rule. Glasser, however, could also mean that a court must have some proof aliunde, but may look at the hearsay statements themselves in light of this independent evidence to determine whether a conspiracy has been shown by a preponderance of the evidence. The Courts of Appeals have widely adopted the former view and held that in determining the preliminary facts relevant to co-conspirators’ out-of-court statements, a court may not look at the hearsay statements themselves for their evidentiary value.
  Both Glasser and Nixon, however, were decided before Congress enacted the Federal Rules of Evidence in 1975. These Rules now govern the treatment of evidentiary questions in federal courts. Rule 104(a) provides: “Preliminary questions concerning . . . the admissibility of evidence shall be determined by the court.... In making its determination it is not bound by the rules of evidence except those with respect to privileges.” Similarly, Rule 1101(d)(1) states that the Rules of Evidence (other than with respect to privileges) shall not apply to “[t]he determination of questions of fact preliminary to admissibility of evidence when the issue is to be determined by the court under rule 104.” The question thus presented is whether any aspect of Glasser’s bootstrapping rule remains viable after the enactment of the Federal Rules of Evidence.
  Petitioner concedes that Rule 104, on its face, appears to allow the court to make the preliminary factual determinations relevant to Rule 801(d)(2)(E) by considering any evidence it wishes, unhindered by considerations of admissibility. Brief for Petitioner 27. That would seem to many to be the end of the matter. Congress has decided that courts may consider hearsay in making these factual determinations. Out-of-court statements made by anyone, including putative co-conspirators, are often hearsay. Even if they are, they may be considered, Glasser and the bootstrapping rule notwithstanding. But petitioner nevertheless argues that the bootstrapping rule, as most Courts of Appeals have construed it, survived this apparently unequivocal change in the law unscathed and that Rule 104, as applied to the admission of co-conspirator’s statements, does not mean what it says. We disagree.
  Petitioner claims that Congress evidenced no intent to disturb the bootstrapping rule, which was embedded in the previous approach, and we should not find that Congress altered the rule without affirmative evidence so indicating. It would be extraordinary to require legislative history to confirm the plain meaning of Rule 104. The Rule on its face allows the trial judge to consider any evidence whatsoever, bound only by the rules of privilege. We think that the Rule is sufficiently clear that to the extent that it is inconsistent with petitioner’s interpretation of Glasser and Nixon, the Rule prevails.
  Nor do we agree with petitioner that this construction of Rule 104(a) will allow courts to admit hearsay statements without any credible proof of the conspiracy, thus fundamentally changing the nature of the co-conspirator exception. Petitioner starts with the proposition that co-conspirators’ out-of-court statements are deemed unreliable and are inadmissible, at least until a conspiracy is shown. Since these statements are unreliable, petitioner contends that they should not form any part of the basis for establishing a conspiracy, the very antecedent that renders them admissible.
  Petitioner’s theory ignores two simple facts of evidentiary life. First, out-of-court statements are only presumed unreliable. The presumption may be rebutted by appropriate proof. See Fed. Rule Evid. 803(24) (otherwise inadmissible hearsay may be admitted if circumstantial guarantees of trustworthiness demonstrated). Second, individual pieces of evidence, insufficient in themselves to prove a point, may in cumulation prove it. The sum of an evidentiary presentation may well be greater than its constituent parts. Taken together, these two propositions demonstrate that a piece of evidence, unreliable in isolation, may become quite probative when corroborated by other evidence. A per se rule barring consideration of these hearsay statements during preliminary factfinding is not therefore required. Even if out-of-court declarations by co-conspirators are presumptively unreliable, trial courts must be permitted to evaluate these statements for their evidentiary worth as revealed by the particular circumstances of the case. Courts often act as factfinders, and there is no reason to believe that courts are any less able to properly recognize the probative value of evidence in this particular area. The party opposing admission has an adequate incentive to point out the shortcomings in such evidence before the trial court finds the preliminary facts. If the opposing party is unsuccessful in keeping the evidence from the factfinder, he still has the opportunity to attack the probative value of the evidence as it relates to the substantive issue in the case. See, e. g., Fed. Rule Evid. 806 (allowing attack on credibility of out-of-court declarant).
  We think that there is little doubt that a co-conspirator’s statements could themselves be probative of the existence of a conspiracy and the participation of both the defendant and the declarant in the conspiracy. Petitioner’s case presents a paradigm. The out-of-court statements of Lonardo indicated that Lonardo was involved in a conspiracy with a “friend.” The statements indicated that the friend had agreed with Lonardo to buy a kilogram of cocaine and to distribute it. The statements also revealed that the friend would be at the hotel parking lot, in his car, and would accept the cocaine from Greathouse’s car after Greathouse gave Lonardo the keys. Each one of Lonardo’s statements may itself be unreliable, but taken as a whole, the entire conversation between Lonardo and Greathouse was corroborated by independent evidence. The friend, who turned out to be petitioner, showed up at the prearranged spot at the prearranged time. He picked up the cocaine, and a significant sum of money was found in his car. On these facts, the trial court concluded, in our view correctly, that the Government had established the existence of a conspiracy and petitioner’s participation in it.
  We need not decide in this case whether the courts below could have relied solely upon Lonardo’s hearsay statements to determine that a conspiracy had been established by a preponderance of the evidence. To the extent that Glasser meant that courts could not look to the hearsay statements themselves for any purpose, it has clearly been superseded by Rule 104(a). It is sufficient for today to hold that a court, in making a preliminary factual determination under Rule 801(d)(2)(E), may examine the hearsay statements sought to be admitted. As we have held in other cases concerning admissibility determinations, “the judge should receive the evidence and give it such weight as his judgment and experience counsel.” United States v. Matlock, 415 U. S., at 175. The courts below properly considered the statements of Lonardo and the subsequent events in finding that the Government had established by a preponderance of the evidence that Lonardo was involved in a conspiracy with petitioner. We have no reason to believe that the District Court’s factfinding of this point was clearly erroneous. We hold that Lonardo’s out-of-court statements were properly admitted against petitioner.
  We also reject any suggestion that admission of these statements against petitioner violated his rights under the Confrontation Clause of the Sixth Amendment. That Clause provides: “In all criminal prosecutions, the accused shall enjoy the right ... to be confronted with the witnesses against him.” At petitioner’s trial, Lonardo exercised his right not to testify. Petitioner argued that Lonardo’s unavailability rendered the admission of his out-of-court statements unconstitutional since petitioner had no opportunity to confront Lonardo as to these statements. The Court of Appeals held that the requirements for admission under Rule 801(d)(2)(E) are identical to the requirements of the Confrontation Clause, and since the statements were admissible under the Rule, there was no constitutional problem. We agree.
  While a literal interpretation of the Confrontation Clause could bar the use of any out-of-court statements when the declarant is unavailable, this Court has rejected that view as “unintended and too extreme.” Ohio v. Roberts, 448 U. S. 56, 63 (1980). Rather, we have attempted to harmonize the goal of the Clause — placing limits on the kind of evidence that may be received against a defendant — with a societal interest in accurate factfinding, which may require consideration of out-of-court statements. To accommodate these competing interests, the Court has, as a general matter only, required the prosecution to demonstrate both the unavailability of the declarant and the “indicia of reliability” surrounding the out-of-court declaration. Id., at 65-66. Last Term in United States v. Inadi, 475 U. S. 387 (1986), we held that the first of these two generalized inquiries, unavailability, was not required when the hearsay statement is the out-of-court declaration of a co-conspirator. Today, we conclude that the second inquiry, independent indicia of reliability, is also not mandated by the Constitution.
  The Court’s decision in Ohio v. Roberts laid down only “a general approach to the problem” of reconciling hearsay exceptions with the Confrontation Clause. See 448 U. S., at 65. In fact, Roberts itself limits the requirement that a court make a separate inquiry into the reliability of an out-of-court statement. Because “ ‘hearsay rules and the Confrontation Clause are generally designed to protect similar values,’ California v. Green, 399 U. S. [149, 155 (1970)], and ‘stem from the same roots,’ Dutton v. Evans, 400 U. S. 74, 86 (1970),” id., at 66, we concluded in Roberts that no independent inquiry into reliability is required when the evidence “falls within a firmly rooted hearsay exception.” Ibid. We think that the co-conspirator exception to the hearsay rule is firmly enough rooted in our jurisprudence that, under this Court’s holding in Roberts, a court need not independently inquire into the reliability of such statements. Cf. Dutton v. Evans, 400 U. S. 74 (1970) (reliability inquiry required where evidentiary rule deviates from common-law approach, admitting co-conspirators’ hearsay statements made after termination of conspiracy). The admissibility of co-conspirators’ statements was first established in this Court over a century and a half ago in United States v. Gooding, 12 Wheat. 460 (1827) (interpreting statements of co-conspirator as res gestae and thus admissible against defendant), and the Court has repeatedly reaffirmed the exception as accepted practice. In fact, two of the most prominent approvals of the rule came in cases that petitioner maintains are still vital today, Glasser v. United States, 315 U. S. 60 (1942), and United States v. Nixon, 418 U. S. 683 (1974). To the extent that these cases have not been superseded by the Federal Rules of Evidence, they demonstrate that the co-conspirator exception to the hearsay rule is steeped in our jurisprudence. In Delaney v. United States, 263 U. S. 586, 590 (1924), the Court rejected the very challenge petitioner brings today, holding that there can be no separate Confrontation Clause challenge to the admission of a co-conspirator’s out-of-court statement. In so ruling, the Court relied on established precedent holding such statements competent evidence. We think that these cases demonstrate that co-conspirators’ statements, when made in the course and in furtherance of the conspiracy, have a long tradition of being outside the compass of the general hearsay exclusion. Accordingly, we hold that the Confrontation Clause does not require a court to embark on an independent inquiry into the reliability of statements that satisfy the requirements of Rule 801(d)(2)(E).
  The judgment of the Court of Appeals is
  Affirmed.
  We intimate no view on the proper standard of proof for questions falling under Federal Rule of Evidence 104(b) (conditional relevancy). We also decline to address the circumstances in which the burden of coming forward to show that the proffered evidence is inadmissible is appropriately placed on the nonoffering party. See E. Cleary, McCormick on Evidence § 53, p. 136, n. 8 (3d ed. 1984). Finally, we do not express an opinion on the proper order of proof that trial courts should follow in concluding that the preponderance standard has been satisfied in an ongoing trial.
  The Advisory Committee Notes show that the Rule was not adopted in a fit of absentmindedness. The Note to Rule 104 specifically addresses the process by which a federal court should make the factual determinations requisite to a finding of admissibility:
  “If the question is factual in nature, the judge will of necessity receive evidence pro and con on the issue. The rule provides that the rules of evidence in general do not apply to this process. McCormick § 53, p. 123, n. 8, points out that the authorities are ‘scattered and inconclusive,’ and observes:
  “ ‘Should the exclusionary law of evidence, “the child of the jury system” in Thayer’s phrase, be applied to this hearing before the judge? Sound sense backs the view that it should not, and that the judge should be empowered to hear any relevant evidence, such as affidavits or other reliable hearsay.’” 28 U. S. C. App., p. 681 (emphasis added).
  The Advisory Committee further noted: “An item, offered and objected to, may itself be considered in ruling on admissibility, though not yet admitted in evidence.” Ibid, (emphasis added). We think this language makes plain the drafters’ intent to abolish any kind of bootstrapping rule. Silence is at best ambiguous, and we decline the invitation to rely on speculation to import ambiguity into what is otherwise a clear rule.
  Given this disposition, we have no occasion to address the Government’s argument, Brief for United States 21-25, that Lonardo’s statements are admissible independent of Rule 801(d)(2)(E).
  We reject any suggestion that by abolishing the bootstrapping rule, the Federal Rules of Evidence have changed the co-conspirator hearsay exception such that it is no longer “firmly rooted” in our legal tradition. The bootstrapping rule relates only to the method of proof that the exception has been satisfied. It does not change any element of the co-conspirator exception, which has remained substantively unchanged since its adoption in this country.