Reg. § 1.166-1(c). A bona fide debt is one that arises from a debtor-creditor relationship based on an enforceable obligation to pay a sum of money. Treas. Reg. § 1.166-1(c). Shaw failed to show that her advance to SRG constituted a bona fide debt that arose from a debtor-creditor relationship. Notably, her behavior was not consistent with that of a traditional lender; she continued to advance money to SRG despite its unstable finances and the company’s failure to repay any interest or principal. Shaw also failed to prove worthlessness as she produced no evidence beyond her and her brother Kenneth’s testimony that SRG had become insolvent. The Tax Court may refuse to accept uncorroborated testimony as dispositive and did so here. See Ruark v. Comm’r, 449 F.2d 311, 312 (9th Cir.1971) (<HOLDING>). Shaw’s argument on appeal that the advance
holding that a court is not bound to accept testimony at face value even when it is uncontroverted if it is improbable unreasonable or questionable internal citation omitted holding that a party is not bound by the testimony of a witness it calls holding that it is not holding the tax court not bound to accept taxpayers uncontradicted testimony if it found the testimony to be improbable unreasonable or questionable holding that where testimony is inherently improbable the court may choose to disregard it