PUBLISH
UNITED STATES COURT OF APPEALS
FOR THE TENTH CIRCUIT

________________ _________________ DIANNA CHRISTINE MURPHY, Plaintiff - Appellee,

v. THOMAS SCHAIBLE, Defendant - Appellant, and SCHAIBLE, RUSS O & COMPANY, C.P.A.’S, L.L.P., Defendant. No. 22-1421

________________ _________________ Appeal from the United States District Court for the District of Colorado (D.C. No. 1:19-C V-02808-WJM-MEH)

________________ _________________ Kendra N. Beckwith (Hilary D. Wells, with her on the brie fs), Lewis Roca Rothgerber Christie LLP, Denver, Colora do, for Defendant-Appellant. Anthony T. Golz (Cory M. Curtis, with him on the brief), Cokinos Y oung, P.C., Houston, Texas, for Plaintiff-Appellee.

________________ _________________ Before HARTZ , McHUGH , and FEDERICO , Circuit Judges.

________________ _________________ HARTZ , Circuit Judge.

________________ _________________ FILED United States Court of Appeals Tenth Circuit 

### July 25, 2024 Christopher M. Wolpert Clerk of Court Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 12 Defendant Thomas Schaible appeals the district-court order denying his motion for judgment as a matter of law that sought to set aside a jury verdict finding him liable for breaching his fiduciary duty to Plaintiff Dianna Murphy, who was the wife of his brother Michael during the relevant events. 1 Thomas was the investment advisor to Dianna and Michael with respec t to an account the two held as joint tenants with rights of survivorship. The alleged breach concerned Thomas’s following Michael’s instructions to transfer virtually all th e cash in the account to a Colorado bank account in anticipation of Mich ael’s then transfe rring the funds to a Mexican bank account controlled solely by Mi chael. This action by Thomas allegedly breached his fiduciary duty to Dianna because he failed to inform her of the proposed transfer when she could have prevented it or to advise her of steps she could have taken to protect herself, de spite his knowledge of the c ouple’s marital difficulties and Dianna’s interest in di viding the couple’s assets. Thomas contends (1) that Dianna did not suffer a legally compensable injury from the transfer of funds by Michael, her joint tenant, who had full legal authority to transfer the funds and (2) that he di d not breach any fiduciary duty to her by following Michael’s instructi ons without informing or a dvising her. We reject both contentions. We also reject Thomas’s argument that Di anna was not entitled to

1 Because the three principa l actors shared the same last name at the time of the relevant events, we hereafter avoid c onfusion by referring to them by their first names. Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 23 prejudgment interest because of alleged procedural deficienci es in district court. We have jurisdiction under 28 U.S.C. § 1291 and affirm the judgment below.
I. BACKGROUND
A. Factual Background Thomas, a licensed investment advisor, wa s the financial advisor and accountant for Michael and Dianna. In particular, he was the couple’s “investment advisor representative” for their investment account with Securities Service Network, Inc. (the SSN account). When they opene d the SSN account in 2007, the couple signed a “Client Advisory Services Agreement” (the Agreement or Client Agreement). Aplt. App., Vol. VII at 1991. It did not authorize Thomas to make investment choices for the couple, and stated that they “shall at a ll times maintain full and comple te ownership rights (i.e., the right to add or withdraw securities or cash . . . ) to all assets held in their account.” Id. at 1997. The Agreement further st ated that the investment-advi sor representative “may act upon instructions fro m any account holder.” Id. at 1998. In 2014 the couple signed an “SSN Account Form,” id. at 1940, which stated that thei r ownership of the SSN account was as joint tenants with rights of surviv orship. Later, they executed standing payment instructions authorizing transfers via bank wires from the SSN account to an account at First Bank of Vail held jointly by the couple. Dianna and Michael began ha ving marital difficulties in late 2016. On December 29, 2016, Dianna emailed one of Michael’s ot her brothers (not Thomas) to tell him of a car crash seriously injuring the adult son of Michael and Dianna. The email also informed him that Michael “wanted a di vorce” and had said he woul d “destroy” Dianna and their Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 34 children. Id. at 2010. She said Michael “got crazy in sane,” that she had called the police, and that “his lack of rational thinking is making me worried.” Id. This email was forwarded to Thomas, who then forwarde d it to his wife, saying, “Not good.” Id. at 2009. On February 24, 2017, Dianna sent a long email to Thomas discussing her marital troubles with Michael and what she perceived as his “ser ious” mental-health issues, and asking about a “facil ity” Michael could be sent to. Id. at 2014. In particular, she told Thomas: [I]t is important that you know that Mike is at the extreme level of instability his motives ac tions and every other moment of each and every day are unpredictable and without any r eality and filled with lies. I worry about our future as I believe he w ill do everything he can to destroy it. So please do not allow him to make any irrational financial decisions [.] That is I believe the only thing that you can really do to help Mike, me and the kids. Id. (emphasis added). Thomas’s response sugg ested the couple take some time apart to evaluate their next steps and said, “I wish I had a simp le solution to this quagmire but coming to Mexico to confront my brothe r will be disastrous and I believe alienate him even further if he indeed needs the help you speak of he needs to come to that realization himself.” Id. at 2013. On March 11 Michael emailed Thomas to ask about the fees being charged on the SSN account and whether they applied to cash holdings. He stated that if they did, “we might be better holding the cash ourselves.” Id. at 2016. At trial Dianna admitted that she had read Michael’s emai ls and that by March 13 she was aware of his inquiry about fees but ne ver mentioned it to Thomas. Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 45 On March 15 Dianna emailed Thomas a list of the coupl e’s joint assets, stating that she had “sent mike this list. It was my beginning point on separating our assets. He would prefer that I just go away and ev erything stays the same. Wish it were that simple. . . . I am wondering thought [sic] the process for separating our interest in terms of voya mutual funds and cash?” Id. at 2020. She went on to discuss ways the couple might divide various other assets. Thomas did not respond to this email, though he forwarded it to Michael on March 31 at Michael’s request. On March 22 Dianna emailed Thomas again, knowing that he was on a ski vacation with his family. She had what she called a “silly question” for him: I have figured out so far that is much more benefi cial for mike and I to distribute our US assets mu tually before any kind of filing. . . . my silly question to you is can I not just request that you distribute our mutual fund accounts cash and . . . cash out the voya and send 50% towards each? I was just wondering if I am empower ed to request such? Do I have any access to request small amounts of di nero? never had to before so don’t really know the rules. . . . I have al ways deeply appreciated your guidance and investment advice. Id. at 2019. Thomas did not respond to this email either, though he also forwarded it to Michael on March 31. On March 30 Dianna emailed Michael to tell him she was driving from Mexico, where the couple lived, to a home they had in Colora do. She testified that at this point she “had had enough.” Id. , Vol. IV at 989–90. Mi chael forwarded this email to Thomas the same day. He also separately emailed Thomas: I really need all the mails from Dianna to you guys. . . . She is not well and I do not agree that sh e can simply, unilaterally decide to walk away and dictate terms. My goal will be to pay all bills as I always do until she decides to end this marriag e. I guess that is what sh e is hell bent on. She Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 56 doesn’t want to live here in Mexico, doesn’t want to live with me . . . Shouldn’t be driving alone to San Diego either. Irrational and irresponsible decisions all the way around. Id. , Vol. VII at 2034. Later that day, Michael emailed Thomas again. He stated, “We do not want to pay any fees on cash at this time so we pr efer to move the cash please. Can you hold on to our investments but transfer the 2.6 [million] cash to our Vail account so as I may transfer it back home here to Mexico.” Id. at 1947. Thomas called Michael to confirm the transfer and to inform him that the account did not have $2.6 million available, and Michael approved the tran sfer of $2.5 million instead. That night, Michael sent Thomas another email to ask about the tax consequences of liquidating all the investments held in the joint SSN account. The total value of the assets in the account, including the $2.5 million in cash, was almost $7 million. The next day, March 31, Thomas confir med to Michael that he had initiated the transfer of the $2.5 million. He also responded to Michael’s email regarding liquidation of the SSN-account assets, explai ning the tax conseque nces of liquidation and making recommendations about how to li quidate the Voya investment. And, as Michael requested, Thomas forwarded him Di anna’s March emails. The cash transfer to the couple’s Vail bank account was not co mpleted until three days later, on April 3. Within a day or two Michael transferre d the $2.5 million from the Vail account to an account in Mexico that Dianna could not access. Before the $2.5 million transfer there ha d never been a transfer from the SSN account larger than $100,000. Thomas never contacted Dianna regarding the transfer Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 67 of cash out of the SSN account. Dianna testified that if she had known about Michael’s plans to transfer the cash in the SSN account she “would have refused to [sic] the transfer of cash to Mexico.” Id. , Vol. IV at 1125–26. On April 7 Dianna sent Thomas seve ral emails, including one in which she asked “what money movements and or trans actions have been made since we last spoke and the current status of our accounts.” Id. , Vol. VII at 2036. In that email she also wrote that “[a]s you know it is my intention to have 50% of our cash, funds, and voya and any other US stuff recognized individually,” explaine d that she had met with a new financial planner and accountant, and requested financial information for tax purposes. Id. Although Thomas did respond to Dianna’s other emails, which discussed tax filing and busi ness entities that sh e shared with Michael, he did not respond to her email asking about money m ovements, the status of the SSN account, and the possible division of the couple’s as sets; nor did he tell her about the $2.5 million transfer that had been completed on April 3. He did, however, forward Dianna’s email to Michael, saying, “Here we go. . .” Id. On April 10 Dianna changed the instru ctions on the SSN account to not allow any activity in it without the express wri tten permission of both parties. While Michael made several further requests fo r funds from the SSN account, no transfers were made while Thomas was the couple’s broker because of the freeze Dianna put on the account. On April 11, 2017, Dianna emailed Thomas to try to establis h a division of the couple’s assets. In that email she explained that “I became aware inadvertently of the Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 78 cash transfer to the Vail account and subsequent transfer, (t he next day I think) to Mike’s personal account in Mexico. So I unde rstand that the balance of the SSN is approximately half of our mu tual assets in the US.” Id. at 2053. She forwarded the email to Michael, adding, “I will assume th at you will continue to pay all of our expenses as you indicated you would to me. As you are in possession of all of our cash, it is logical to me this is your intention.” Id. at 2052. Michael emailed Thomas that day, explaining that “[t]here will be no division of anything between Dianna and I. . . . I would ignore her. A ny division of cash or assets will be the result of divorce settlement in Mexico and it certainly w ill not include an even division of these funds.” Id. at 2051. Thomas responde d, “Thought as much.” Id. Thomas did not respond to Dianna’s email. Dianna filed for divorce in June 2017. Thomas resigne d as investment advisor for the SSN account in December 2017.
B. Procedural History Dianna filed suit against Thomas in October 2019, alleging that Thomas breached his fiduciary duty to her by facilita ting the transfer of funds out of the SSN account without her knowledge or consent and failing to inform her of it before or after the transf er was made. 2 The case proceeded to jury trial. At the close of Dianna’s case-in-chief, Thomas moved for judgment as a matter of law under Fed. R. Civ. P. 50(a). The

2 Dianna also sued Thomas’s company, Schaible, Russo & Company, C.P.A.’s, L.L.P. (SRC). The jury found for SRC a nd she does not appeal that verdict. Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 89 district court granted the mo tion in part but denied the motion with respect to the claim addressed in this appeal. In June 2022 the jury found for Dia nna, awarding her $600,000 in economic damages, which were based en tirely on the withdrawal by Mi chael of the funds in the
SSN account. Two weeks after the verdict, Dianna f iled a “Motion for Prejudgment Interest and Entry of Judgment,” and in December Thomas filed a motion for judgment as a matter of law under Fed. R. Civ. P. 50(b). In June 2023 the district court awarded Dianna $415,083.26 in prej udgment interest, denied T homas’s Rule 50(b) motion, and entered a separate “final judgment.” On appeal Thomas challenges the deni al of his Rule 50(b) motion and the award of prejudgment interest. We af firm the district-court judgment.
II. ANALYSIS
A. Standard of Review “We review a district court’s denial of a Rule 50 motion de novo, applying the same standards [that gove rn] the district court.” Bill Barrett Corp. v. YMC Royalty
Co. , 918 F.3d 760, 766 (10th Cir. 2019) (internal quotation mark s omitted). “A party is entitled to judgment as a matter of law only if the cour t concludes that all of the evidence in the record reveals no legally su fficient evidentiary ba sis for a claim under the controlling law.” Id. (brackets and internal quota tion marks omitted). “The court draws all reasonable inferences in favor of the nonmoving party and does not weigh evidence, judge witness credibility, or challenge the fa ctual conclusions of the jury.” Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 910 Id. (internal quotation marks omitted). We review de novo the proper interpretation of the Rules of Civil Procedure. See In re Unioil, Inc. , 962 F.2d 988, 990 (10th Cir. 1992). Because the parties ag ree that Colorado substan tive law applies, we will proceed under that assumption. See Butler v. Daimler Trucks N. Am., LLC , 74 F.4th 1131, 1140–41 (10th Cir. 2023) (applying Kansas law wh ere parties agreed it applied).
B. Breach of Fiduciary Duty It is undisputed that Thomas was act ing as a fiduciary to Dianna when Michael’s transfer occurred. Thomas raises only two challe nges to the denial of his Rule 50(b) motion to set aside the jury’s verdict on Dianna’s claim that he breached his fiduciary duty to her. Firs t, he argues that because Di anna and Michael were joint tenants who each had an ownership intere st in the entirety of the SSN account, Dianna incurred no legally cognizable damage s when Michael exercised his right to possession of the cash in the account. S econd, Thomas argues th at because Michael and Dianna were joint tenants on the acco unt and he was permitted by the Client Agreement to act under instructions from either account holder, he had no fiduciary duty to notify Dianna about the transfer, refuse to perform it, or take any other action for Dianna’s protection. We are not persuaded.
1. Joint Tenancy and Damages Although Thomas contends th at he did not breach any fiduciary duties owed to Dianna, his first argument on appeal is that even if he did, she suffered no legally cognizable damages. He points out that any loss she incurred resulted from the Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 1011 transfer of funds from the SSN account but that the transfer was on the order of Michael, who, as a joint tenant, had full lega l authority to make such an order. How, Thomas argues, could Dianna suffer a le gal injury from a fu lly legal act of Michael’s? We proceed to expl ain, starting with a brief primer on joint tenancy with rights of survivorship, the capacity in wh ich Dianna and Michael owned their SSN

account. “[J]oint tenancy is a form of ownership in which each joint tenant possesses the entire estate, rather than a fractional share.” Taylor v. Canterbury , 92 P.3d 961, 964 (Colo. 2004) (citing United States v. Craft , 535 U.S. 274, 280 (2002) (“The common law characterized each joint tenant as possessi ng the entire estate, rather than a fractional share: Joint-tenants have one and the same interest held by one and the same undivided possession.” (cleaned up))). But though “each co-owner is entitled to possess and enjoy the entire estate” while the joint tenancy is intact—a feature that “enables th e survivor of the joint tenants to obtain sole possession of the whole property without any further conve yance”—each “joint tenant has an undivided fractional share of the tenancy. If the joint te nancy is ever terminated by severance, the joint tenant will receive only the portion of the property that corresponds to that fracti onal share.” 7 Powell on Real Property § 51.03[2]. Proceeding on the assumption that each te nant had a right to withdraw all the money in the account, Thomas claims that “[a] s a matter of law, a trier of fact cannot award damages to a joint tenant based on the amount of money withdrawn from an account by another joint tenant.” Aplt. Br . at 27. And because at trial the only Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 1112 evidence of economic damages permitted by the court was the reduction in value of the jointly held SSN account resulting fro m Michael’s withdrawal, Thomas argues that he is entitled to judgment as a matter of law on Dianna’s claim. See Miller v. Byrne , 916 P.2d 566, 575 (Colo. App. 1995) (“To prove a claim for breach of fiduciary duty a plaintiff must demonstrate . . . that he or she has incurred damages and that the defendant’s breach of fiduc iary duty was a cause of the damages sustained.”). This argument might well be a winner if Dianna were suing her cotenant Michael for withdrawing the money from th e SSN account. But Dianna is not suing her cotenant. She has not argued that Michael lacked lawful aut hority to move the funds. Her claim is that Thom as had a fiduciary duty to protect her from Michael’s “lawful” actions. Thomas does not dispute that Dianna was financially injured by Michael’s transfer of the funds , which left her with less mone y. And that is all that is necessary to show that Thom as caused damages to her. There is nothing novel about holding a defendant (like Thomas) liable for injury to a plaintiff (like Dianna) caused by a lawful interaction of the plaintiff with a third party (like Michael). For example, a third-party business A may have every right not to enter into a cont ract with the plaintiff. Bu t if the defendant improperly induced third-party A not to do business w ith the plaintiff, the defendant may be liable to the plaintiff. See, e.g. , Omedelena v. Denver Options, Inc. , 60 P.3d 717, 719–721 (Colo. App. 2002) (defendants liable for tort ious interference with prospective economic advantage that pl aintiff sought with a third party). Or, to give Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 1213 an example where the defendant is a fiduciary of the plaintiff, an attorney who negligently misrepresents the tax consequen ces of a client’s lawful purchase of an investment from a third party may be lia ble for the loss sust ained when no tax advantages materialize. See Restatement (Third) of Tort s: Liability for Economic Harm § 5 Negligent Misrepresentation Ill. 5 (2020). Thus, even if Michael lawfully transferred the funds from his joint account with Dianna, that would not in itself relieve Thomas of liability fo r failure to protect Dianna from economic loss suffered because of the transfer. We reject Thomas’s argumen t that Dianna could not have suffered any legally cognizable economic damages as a result of Michae l’s transfer.
2. Breach of Fiduciary Duty Thomas does not dispute that he stood as a fiduciary to Dianna with regard to the SSN account and had the typical dutie s of a fiduciary. Those duties under Colorado law have been outlined by the State’s highest court: A fiduciary is a person ha ving a duty, created by his undertaking, to act primarily for the benefit of anothe r in matters connected with the undertaking. A fiduciary has a duty to deal with utmost good faith and solely for the benefit of the benefici ary. A fiduciary’s obligations to the beneficiary include, among other thi ngs, a duty of l oyalty, a duty to exercise reasonable care and skill, a nd a duty to deal impartially with beneficiaries. Destefano v. Grabrian , 763 P.2d 275, 284 (Colo. 1988 ) (affirming fiduciary liability of priest to husband and wife for whom he provided marriage coun seling) (citations and internal quotation marks omitted) (citing Restatemen t (Second) of Trusts §§ 170, 174, 183 (1959)); see Paine, Webber, Jackson & Curtis, Inc. v. Adams , 718 P.2d 508, Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 1314 515 (Colo. 1986) (agent who is a fiduciary regarding a customer’s account has “wideranging duties in managing the customer’s ac count in accordance with the customer’s needs and objectives”); cf. Colo. Rev. Stat. Ann. § 15-1-304 (mandating that fiduciaries managing and invest ing property for others “sha ll exercise the judgment and care, under the circumstances then prevailing, which men of prudence, discretion, and intelligence ex ercise in the management of the property of another”). “A broker who becomes a fiduciary of his client must act with utmost good faith, reasonable care, and loyalty concerning the cu stomer’s account, and owes a duty . . . to act responsib[ly] to protect [the customer’s] inte rests, to keep the cust omer informed as to each completed transaction, and to explain fort hrightly the practical impact and potential risks of the course of dealing in which the broker is engaged.” Rupert v. Clayton Brokerage Co. of St. Louis , 737 P.2d 1106, 1109 (Colo. 1 987). “The law imposes a strict duty of disclosure upon a fiduciary,” which includes the requirement that the fiduciary “make a full and complete disclosure of all facts relative to the subject of his agency which it may be material to the principal to know.” Wheeler v. Carl Rabe, Inc. , 599 P.2d 902, 904 (Colo. 1979) (internal quotation marks omitted); see also Olsen v. Vail Assocs. Real Est., Inc. , 935 P.2d 975, 978 (Colo. 1997) (same); Adams , 718 P.2d at 514 n.6 (affirming jury verdict where ju ry was instructed that a fiduciary stockbroker “must make full and complete disclosure of all facts wh ich may be material for his customer to know”); Restatement (Third) of Trusts § 82(1)(c) & cmt. d (2007) (a fiduciary trustee must “inform . . . beneficiaries of impor tant developments and information that Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 1415 appear reasonably necessary for the beneficiar ies to be aware of in order to protect their interests”). The nature and scope of the duty owed by a fiduciary are determined by the court as a matter of law fro m the factual context of the relationship found by the factfinder or stipulated by the parties, wh ile the factfinder dete rmines whether there has been a breach of any fiducia ry duty defined by the court. See Command Commc’ns, Inc. v. Fritz Cos. , 36 P.3d 182, 186 (C olo. App. 2001); see also Raleigh v. Performance Plumbing & Heating , 130 P.3d 1011, 1015 (Colo. 2006) (in negligence case, “[w]hether a specific defendant owes a duty to a specific plaintiff under the circumstances involved with a tort claim is a question of law we review de novo”). Thomas does not dispute th at he owed Dianna all th e aforementioned fiduciary duties in regard to the SSN account. Instead he claims that, as a matter of law—given Michael and Dianna’s equal rights as joint tenants to withdraw all the SSN-account funds and the Client Agreemen t authorizing Thomas to act on the authority of either of them—he had no specific duty in this circ umstance to refuse Michael’s transfer request, to inform Dianna abou t the transaction, or otherw ise to advise her regarding her options on how to retain control of the funds in the SSN account. We cannot
agree. We think Thomas’s fiduciary duties in this respect are well-defined by Colorado law. But he claims support for his position from a non-Colorado opinion, Zimmerman v. Merrill Lynch, Pierce, Fenner & Smith, Inc. , 391 N.W.2d 353, 356 (Mich. Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 1516 App. 1986)

. The court in that case, rejecting a claim that a broker had breached his fiduciary duties, declared that “[b]rokers generally are not required to individually apprise co-owners of a joint acco unt as to the independent tr ansactions of other owners. Nor are brokers required to disregard orders from one owner of a joint account where there is a perceived conflict of interest with another owner.” The case involved a mother and her son who were co-owners of a joint brokerage account. See id. at 354–55. Eventually, over the course of four year s, the son withdrew all $250,000 from the account, and the mother sued the brokerage firm, allegi ng breach of fiduciary duty. See id. at 355. During the entire period the mother was informed of each transaction by a mailed confirmation and throu gh a monthly statement, yet she never objected to them. See id. at 356. The court said that “[a]ny duty im posed upon defendant to inform plaintiff was fulfilled by those mailings.” Id. We need not decide the ex tent to which we think Colorado courts would agree with Zimmerman because this case is readily distinguishable. Zimmerman , unlike our case, did not involve a fiduciary who failed to inform his client of a major transaction (one 25 times greater than any other single tr ansaction up to that point); the contested withdrawals took place over the course of four years, not, as here, on a single occasion; each withdrawal was reported to the plain tiff in a confirmation mailing and a monthly statement; and while the plaintiff in Zimmerman argued that “it became apparent that [her son] was depleting the account contrary to the plaintiff’s purpose and interest,” id. , the fiduciary broker was not made aware, as Thomas was, of significant interpersonal issues between the two joint tenants, nor was he ever instructed, as Thomas was, not to allow Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 1617 the other joint tenant to “make any irrationa l financial decisions,” Aplt. App., Vol. VII at 2014, or that the complaining jo int tenant would like to sp lit the account’s assets in contemplation of a divorce. Moreover, if we are to look to out-of-s tate cases, we think the language in a case relied on by Dianna is clos er in point and more persua sive in the context before
us. In Leuzinger v. Merrill Lynch, Pierce, Fenner & Smith, Inc. , 396 S.W.2d 570, 576 (Mo. 1965) , the court held: Pursuant to the general duty of a st ockbroker to act in good faith with customers and to make a complete and full disclosure of all material facts concerning a transaction, if th e stockbroker knows of facts and circumstances which would lead an or dinarily careful and diligent person to believe that one join t tenant of a joint broke rage account was in the process of wrongfully converting to his own uses and purposes the interest of the other joint tenant, a dut y to inform the latter would arise, and in such case the broker would be derelict in disbursing the whole account to the joint tenant under susp icion, without first informing the other and obtaining consent and approval to the disbursement. The brokerage firm was not liable, howev er, because there was “nothing in the admitted facts to indicate . . . anything which under the circumstances would have aroused the suspicions of an ordinar ily careful and diligent stockbroker.” Id. at 577. A later case, Roth v. Roth , 571 S.W.2d 659, 670 (Mo. App. 1978), relied on this language from Leuzinger to hold a fiduciary broker liable for a breach of his fiduciary duty to the plaintiff, a joint-te nant on a brokerage account, where the broker allowed the transfer of all the assets in the account to the other joint tenant while “[k]nowing of facts which should have led an ordinarily careful and diligent broker to believe a conversion might be taking place” and without informing the plaintiff or Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 1718 obtaining his consent to the transfer. See also Wood v. Ja ck Carl Assocs., Inc. , 782 F.2d 83, 87 (7th Cir. 1986) (discussing the Leuzinger theory of fiduciary duty in the case of a joint brokerage account). We think it clear that under the Leuzinger approach a jury could permissibly find Thom as liable for breaching his fiduciary duty to Dianna insofar as he failed to halt or delay Michael’s withdraw al of the cash, to inform her of the transfer, or to inform her of her right s in regard to the account despite “know[ing] of facts and circumstances which would lead an ordinarily careful and diligent person to believe that one joint tenant” was about to take steps contrary to the wishes of the other joint tenant and deleterious to the other joint tenant’s interests. Leuzinger , 396 S.W.2d at 576. In any event, we do not rely on out-o f-state authority. Colorado fiduciary-duty law is sufficient for us to answer in the affirmative th e question whether Thomas may be held liable, as a matter of law, fo r his acts and omissions relating to the withdrawal of the SSN account’s cash. Though in his appellate briefs Thomas insists that he had no duty to disobey Michael’s transfer instructi on, we think the jury could permissibly find Thomas liable fo r a breach of fiduciary duty. Most prominently, the jury could find th at Thomas breached the “strict duty” imposed on a fiduciary to “mak e a full and complete disclosu re of all facts relative to the subject of his agency which it may be material to the principal to know.” Wheeler , 599 P.2d at 904 (inter nal quotation marks omitted) . In this context, information is material when it woul d assume “actual significance” in the deliberations of the fiduciary’s client, or when it would have “significantly altered Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 1819 the total mix of information available” to the client in regard to the object of the fiduciary duty. Olsen , 935 P.2d at 979. Despite being aware of the couple’s marital difficulties and the fact that Dianna was driving from Mexico to Colorado around the time Michael requested the tr ansfer; despite Dianna’s que stions about separating the couple’s assets, which suggested that a divorce was contem plated and that any large money movements would be information sh e would like to know; despite Michael’s request for all the cash in the SSN account , a transfer 25 times larger than any previous transaction; and despite Dianna’s request that he not “allow [Michael] to make any irrational financial decisions,” Aplt. App., Vol. VII at 2014, Thomas did not inform Dianna of the transfer or of her ability to freeze the account or change the account’s payment instructions . Indeed, even when Dianna explicitly asked, a few days after the transfer had been comp leted, “what money movements and or transactions have been made since we la st spoke and the current status of our accounts,” id. at 2036, Thomas failed to inform her of it, when ther e was apparently still time for her to block th e transfer to Mexico from the Vail bank. And Dianna testified that had she known a bout it, she “would have refuse d to [sic] the transfer of cash to Mexico,” id. , Vol. IV at 1125–2 6; and she froze the account once she learned of the transfer. In these ci rcumstances, the jury could fi nd that it was material for Dianna to know that all the cash in the joint account was being withdrawn, and that Thomas’s failure to inform her of that fact constituted a breach of his fiduciary duty.
See Restatement (Third) of Ag ency § 8.11 (2006) (“An agent has a duty to use reasonable effort to provide the principal with facts that the agent knows, has reason Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 1920 to know, or should know when . . . the agent knows or has reason to know that the principal would wish to have the facts or the facts are mate rial to the agent’s duties to the principal.”); cf. Restatement (Third) of Trus ts § 82(1)(c) & cmt. d (2007) (trustee fiduciaries must “inform fairly repres entative beneficiaries of important developments and information that appear reasonably necessary fo r the beneficiaries to be aware of in order to protect their interests”). The jury could also find that Thomas breached his duty to “deal impartially with beneficiaries.” Destefano , 763 P.2d at 284. Dianna sent Thomas multiple emails asking for advice on how to divide the assets in the SSN account, emails to which he never responded. He also ne ver responded to her request asking about the status of the account and if any money movement s had occurred. But Thomas responded promptly to Michael’s questions about th e tax consequences ofliquidating the SSNaccount assets, his request that Thomas forward him Dianna ’s emails, and of course his request to initiate the tr ansfer of all the cash in th e account. This difference in treatment was sufficient to allow the jury to find that Thomas breached his fiduciary duty of impartiality. See McNeil v. McNeil , 798 A.2d 503, 509–10 (Del. 2002) (fiduciary trustees violated the duty of impartiality by failing to furnish to one beneficiary important information that they furnished to other beneficiaries). When the fiduciary knows his beneficiaries have conf licting desires, he cannot simply pick his favorite, particularly when the choice is based on personal concer ns, such as filial affection. See Taylor v. Taylor , 381 P.3d 428, 431 n.1 (Colo. App. 2016) (“A fiduciary is required to act with good faith and loya lty unaffected by personal motives.”). Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 2021 There may be sufficient evidence to esta blish other breaches by Thomas of his fiduciary duties, but these two will suffice. Thomas nevertheless insists that under “C olorado law, the parties’ contractual agreement supersedes common la w duties,” Aplt. Reply Br. at 12, and therefore, as a matter of law, he did not breach any fiduc iary duties in obeying Michael’s transfer order because the Client Agreement gave hi m the authority to act under instructions from either joint tenant. See Rocky Mountain Expl., Inc. v. Davis Graham & Stubbs
LLP , 420 P.3d 223, 235 (Colo. 2018) (“Even when a fiduciary relationship exists . . . the parties to that relati onship may modify—or even di sclaim—that relationship” by contract). We disagree. We remind Thomas that fiduciary dutie s are not dependent on the contract. See, e.g. , Bailey v. Allstate Ins. Co. , 844 P.2d 1336, 1339 (Colo. App. 1992) (“[T]he existence of a contract between a fiduciary and beneficiary is secondary to the nature of a true fiduciary relationship.”); cf. Hess Oil Virgin Isl ands Corp. v. UOP, Inc. , 861 F.2d 1197, 1202 (10th Cir. 1988) ( “A party may be liable in tort for breaching an independent duty towards another, even wh ere the relationship creating such a duty originates in the parties’ c ontract.”). To be sure, in so me circumstances a contractual provision could have limited Thomas’s fiduc iary duties. But we need not determine the extent to which Colorado law allows fi duciary duties to be limited by contract, because the parties’ contract did not conf lict with Thomas’s fiduciary duties. The agreement says only that the investment advisor “ may act upon instructions from any account holder,” Aplt. App., Vol. VII at 1998 (emphasis added); it contains no Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 2122 command that the advisor must obey either account holde r’s instructions no matter the circumstances. Neither does it include an express disclaimer of Thomas’s fiduciary duties. See Rocky Mounta in Expl., Inc. , 420 P.3d at 235 (a party had no fiduciary obligation where the parties’ contract clearly and unambiguously disclaimed any fiduciary rela tionship). Thus, to the extent that Thomas’s fiduciary duties demanded that he delay or refuse to process the transfer, the Client Agreement posed no obstacle. Further, even if Thomas is correct that he had to honor Michael’s transfer request, the Client Agreement did not preclude him from performing the other fiduciary duties that he owed Dianna. In particular, nothing in the agreement prevented him from informing Dianna about the transfer, or from informing her of her right to change the payment instruct ions on the SSN account to require written authorization by both account holders, a right she in fact exercised shortly after learning about the transfer. Thus, we affirm the denial of Thomas ’s Rule 50(b) motion. In doing so we emphasize the narrowness of our ruling. This , we hope, is an ex treme case. We are not saying that a fiduciary to joint-tenant account holde rs needs to affirmatively investigate whether there exis ts a conflict between his clie nts before he follows their individual instructions, particularly when there is legitimate need for speed in executing a transaction. We hold only that in circumstances simi lar to this case— where the jury could properly find that Th omas was well-informed of the conflict between his clients; that T homas treated his clients disp arately, apparently for the Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 2223 improper personal motive of filial affection; and that the circumstances of Michael’s transfer put Thomas on notice that it was likely harmful to Dianna—he had fiduciary duties to inform her of the requested transf er in time for her to protect her interests and to respond to related requests for info rmation. His failure to do so in those particular circumstances just ified the jury’s finding that he breached his fiduciary duties to Dianna.
C. Prejudgment Interest Thomas also argues that th e district court’s award of prejudgment interest was procedurally flawed and should be reversed. The jury verdic t was noted in the district court docket on June 7, 2022, but there was no entry of a judgment, see 11 Charles Alan Wright, Arthur R. Miller & Mary Kay Kane, Federal Practice & Procedure § 2785 (3d ed. 2024) (Wright & Miller) (“Mere notation of a verdict is not entry of judgment.”), and no separate “final judgmen t” document was issued. Dianna filed her motion for prejudgment interest on June 20. On June 28, 2023, more than a year later, the district court granted the motion a nd entered a separate “final judgment” document. Thomas contends that the district cour t’s grant of the moti on was too late. He reasons as follows: Because th e district court did not file a separate document setting out the June 7, 2022 jury verdict as a “f inal judgment,” final judgment was entered on November 4, 2022, 150 days after the verdict, by opera tion of Fed. R. Civ. P. 58(c)(2). And because the court failed to address Dianna’s motion for prejudgment interest before the 150-day deadline, it was “denied . . . by operation of law” when Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 2324 final judgment was entered on N ovember 4, 2022. Aplt. Br. at 54. He contends that if Dianna wanted to seek prejudgment intere st, she was required to do so by filing a Rule 59(e) motion within 28 days after fi nal judgment was entered on November 4, 2022, and that, because she did not, the dist rict court had no authority to grant the motion in June 2023. We reject the argument. It misconstr ues the rules regarding finality of judgments. Those rules are intricate. To prop erly resolve the issue before us, we must review them in some detail. To begin with, courts traditionally have said that a judgment is not “final” under 28 U.S.C. § 1291, which provides fe deral appellate jurisdiction over final decisions, until the district cour t has disposed of all claims against all parties, leaving nothing for the district court to do beyond ministerial tasks. See Catlin v. United
States , 324 U.S. 229, 233 (1945) (“A ‘final decision’ genera lly is one which ends the litigation on the merits and leaves nothi ng for the court to do but execute the judgment.”); Dodge v. Cotter Corp. , 328 F.3d 1212, 1221 (10th Cir. 2003) (“[T]o be final, a decision must reflect the termination of all matters as to all parties and causes of action.” (internal quot ation marks omitted)); Est. of Cummings, by and through Montoya v. Cmty. Health Sys., Inc. , 881 F.3d 793, 805 (10th Cir. 2018) (judgment was final when it left distri ct court with nothing more th an “ministerial tasks” to perform). The time at which final judgment is entered is consequential. Most importantly, it starts the clock running on th e time for appeal. But it also controls the Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 2425 time for filing postjudgment motions. The date of entry of judgment should therefore not be ambiguous. Unfortunately, however, th is seemingly simple issue has presented problems. At one time the problem was in determining whether a document actually constituted a judgment. For example, an opi nion issued by the district court might include language stating that a motion fo r summary judgment was granted but omit other matters generally considered elements of a judgment. Hence, the Rules of Civil Procedure were revised in 1963 to require that the judgment ordinarily be “set out in a separate document.” Fe d. R. Civ. P. 58(a); 3 see id. advisory committee’s note to 1963 amendment; see also Bankers Tr. Co. v. Mallis , 435 U.S. 381, 38 5 (1978) (Rule 58(a) “made clear that a party need not file a notice of app eal until a separate judgment has been filed and entered,” but parties can waive this separate-document requirement). The entry of such a separate document did not, however, eliminate the requirement of finality. Even when such a document was entered a circuit court could, indeed was required to, reject an appeal because there was no final judgment, as when, for example, the district court’s order had not unambiguously disposed of a claim or counterclaim by a party. See, e.g. , Alman v. Taunton Sportswear Mfg. Corp. , 857 F.2d 840, 842–43, 844 (1st Cir. 1988) (although district court entered a separate document setting forth its decision, the j udgment was not yet final and appealable

3 A separate document is not required fo r “an order disposing of a motion: (1) for judgment under Rule 50(b); (2) to ame nd or make additional findings under Rule 52(b); (3) for attorney’s fees under Rule 54; (4) for a new trial, or to alter or amend the judgment, under Rule 59; or (5) for relief under Rule 60.” Fed. R. Civ. P. 58(a)(1)–(5). Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 2526 because it failed to una mbiguously dispose of all claims at issue); St. Mary’s Health Ctr. of Jefferson City v. Bowen , 821 F.2d 493, 496–97 (8 th Cir. 1987) (although district court complied with the separate document require ment, the order set out in that document was not final b ecause it failed to dispose of several claims); 11 Wright & Miller § 2785 (“It should be borne in mind that Rule 58 states how a judgment is entered. It does not speak to whether a judgment entered in this fashion is a ‘final judgment’ for purposes of appeal.” ). What the separate-document requirement did do was reduce confusion concerning th e timing of the final judgment. Still, timing problems remained. The “s imple separate document requirement [was] ignored in many cases,” with the result that the times to appeal and to file postjudgment motions ran inde finitely. Fed. R. Civ. P. 58(a) advisory committee’s note to 2002 amendment. The Rule was th erefore amended again in 2002 to provide that if the court fails to se t out an otherwise final judgm ent in a separate document, the judgment becomes final by operation of law 150 days after its entry in the civil docket. See id. 58(c)(2) (where a separate docum ent is required, “judgment is entered . . . when the judgme nt is entered in the civil docket under Rule 79(a) and the earlier of these events occu rs: (A) it is set out in a separate document; or (B) 150 days have run from the entry in the civil docket”). Again, however, this Rule cannot cure lack of finality of the judgment. Its purpose is merely to clarify timing. It may be helpful in this context to distinguish between what we can call substantive and technical finality. A judgment is substantively final when the court has disposed of all matters as to all part ies and causes of acti on, leaving it nothing Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 2627 but ministerial tasks to complete. See Dodge , 328 F.3d at 1221; Est. of Cummings , 881 F.3d at 805

. That substantively final ju dgment ordinarily becomes technically final—starting the time running to file an appeal or subm it postjudgment motions— only when it is entered in a separate documen t or after 150 days have elapsed since it was entered in the civil docket. See Fed. R. Civ. P. 58(c)(2); Alman , 857 F.2d at 842 (“[E]ven a decision that completely disposes of a case’s merits can lack finality for the purposes of section 1291 if it fails to comport with the technical dictates of Rules 58 and 79(a) of the Federal Rules of Civil Procedure.” (emphasis added)). Thomas’s error is in failing to disti nguish between substantive and technical finality. Yes, the judgment against him may have been on its face technically final upon the expiration of 150 days after the ve rdict was entered, but there could be no final judgment until there wa s a substantively final judgment. We therefore examine when there was a substantivel y final judgment against him. The jury verdict disposed of all issues then before the court. Ordinarily, that would quickly become a final judgment. See Fed. R. Civ. P. 58(b)(1) (“[U]nless the court orders otherwise, the clerk must, without awaiting the court’s direction, promptly prepare, sign, and enter the judg ment when: (A) the ju ry returns a general verdict.”). In this case, th e clerk did not enter judgment on the verdict. But even if judgment had been entered, its finality coul d be suspended upon the timely filing of a postjudgment motion. See Hogan v. Pilg rim’s Pride Corp. , 73 F.4th 1150, 1159 n.8 (10th Cir. 2023) (filing of a timely Rule 59(e) motion “s uspends the finality of the judgment” (internal quotation marks omitt ed)). Relevant here, a “postjudgment Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 2728 motion for discretionary prejudgment interest constitutes a motion to alter or amend the judgment under Rule 59(e).” Osterneck v. Ernst & Whinney , 489 U.S. 169, 175 (1989). And a postjudgment motion to alter or amend a judgment is timely if filed “no later than” 28 days after en try of judgment, Fed. R. Ci v. P. 59(e), even if filed before the judgment beco mes technically final, see Hilst v. Bowen , 874 F.2d 725, 726 (10th Cir. 1989) (“A lthough Rule 59 motions are to be served not later than ten [4] days after entry of judgment, courts and commentators gene rally agree that this tenday limit sets only a maximu m period and does not precl ude a party from making a Rule 59 motion before a formal judgment has been entered.”); Fed. R. Civ. P. 59(e) advisory committee’s note to 1995 amendment (“The phrase ‘no later than’ is used— rather than ‘within’—to in clude post-judgment motions that sometimes are filed before actual entry of the judgment by the clerk.”). Dianna’s filing of her motion for prejudgment interest (within 28 days of the jury verdict) was thus timely, and that timely postjudgment motion suspended the substantive finality of the judgment 5 until it was resolved by the district court. See Dodge , 328 F.3d at 1221 (judgment was not final until pending prejudgment-interest motion was resolved, as “[p]rejudgment

4 When Hilst was decided, Rule 59 required th at 59(e) motions be served no later than 10 days after entry of judgment. In 2009 the period to file a Rule 59(e) motion was expanded from 10 days to 28 days. See Fed. R. Civ. P. 59(e) advisory committee’s note to 2009 amendment. 5 Before the filing of the motion for prej udgment interest, all issues before the court had been resolved by the verdict, so there was substantive finality. But perhaps the district court was antic ipating a motion for prejudgmen t interest and therefore instructed the clerk not to enter judgment on the verdic t (which would have been necessary for technical finality). Appellate Case: 22-1421 Document: 010111085110 Date Filed: 07/25/2024 Page: 2829 interest is a portion of the dama ges and thus is an integral part of the merits decision” that must be resolved before final judgm ent). Thomas’s theory that the motion was rejected by operation of law by virtue of the 150-day rule is therefore unsound. We see no procedural defect in the di strict court’s award of prejudgment interest.
III. CONCLUSION The judgment of the district court is AFFIRMED

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