Tax Court Rules $16.5 Million Art-Deal Wire Was Taxable Income, Not a Loan, in Tunkl

The U.S. Tax Court ruled September 10, 2026 that $16.5 million wired to an art broker's company for a planned Picasso purchase was taxable income in the year it arrived, rejecting arguments that the money was a loan or a customer deposit. The decision, Tunkl v. Commissioner, T.C. Memo. 2026-83, sustained a federal income tax deficiency of $5,142,307 for 2018, according to an analysis by Current Federal Tax Developments.

What happened

David Tunkl, an art broker for more than 45 years, ran his business informally through Ganymede International, an S corporation he wholly owned. In January 2018, gallery founder Robert Mnuchin wired $16.5 million to the company with no restrictions attached. The two intended to buy Pablo Picasso's Man with Ice Cream Cone for $18.5 million and resell it for $30.5 million.

Five days after the money arrived, Tunkl used $17.4 million to complete the purchase of a Francis Bacon painting in a separate deal. The Picasso transaction collapsed by late April. In June, Mnuchin's lawyers presented a demand note that characterized $44 million across six failed deals, including the $16.5 million, as a personal debt. By 2019, Tunkl had repaid $2.5 million through an assignment of equity.

Why the court found income

Under Section 61 of the Internal Revenue Code, gross income means all income from whatever source derived unless a specific exclusion applies. The Supreme Court's 1955 Glenshaw Glass decision reads that as covering accessions to wealth, and its 1961 decision in James v. United States holds that money is income when the recipient controls it enough to derive readily realizable economic value from it.

Judge Landy found that the absence of restrictions on the wire, and Tunkl's use of the funds for another deal, showed that kind of control. The court rejected the customer deposit theory because Mnuchin was a profit-sharing co-investor rather than a customer and no repayment obligation existed when the money moved. Applying the Ninth Circuit's multi-factor test for a genuine loan, the court found no promissory note at the time of the transfer, no interest, no repayment schedule, no collateral and little actual repayment. The parties had behaved like joint venturers, and a demand note drafted months later could not change the character of the original transfer.

The after-tax math

Example with round numbers: a collector receives an unrestricted $1,000,000 advance from a partner toward a joint purchase and spends it on something else before any loan papers are signed. If the advance is treated as income and the collector is already in the top bracket, which in 2026 applies to joint filers with taxable income above $768,700, the federal income tax would be about $370,000, before interest and any penalties. If the deal is later unwound and money is repaid, recovering tax paid on an earlier year is not automatic and turns on separate rules.

The contrast with a documented loan is stark. Borrowed money is not income because the borrower owes it back from the start. The difference in Tunkl was not the size of the transfer but the lack of any contemporaneous evidence of that obligation.

Who is affected

The ruling is most relevant to collectors, dealers, private investors and business owners who move large sums informally on handshake terms, including joint purchases of art, real estate or private company stakes. It also applies to anyone who receives money from a co-investor and has discretion over how it is spent.

Practices often discussed with counsel

• Documenting advances at the time of transfer with a signed note, an interest rate, repayment terms and, where appropriate, collateral.
• Holding co-investor funds in segregated accounts with written limits on their use.
• Recording joint ventures in a partnership or operating agreement rather than relying on email and conversation.
• Reviewing with a CPA, before the return is filed, whether any large receipt during the year could be treated as income.

What to watch

The analysis did not address penalties or any appeal. The broader lesson for high-value private deals is timing: paperwork signed after the money moves carries little weight when the IRS asks what the transfer was on the day it arrived.

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