# What the Private Market Does to the Public Record > By the Art Basel and UBS estimates, most art value never passes through a public bid. Christie's says its three largest sales of 2025 were private, and none has a published price. > The Study - 2026-08-02 > Canonical HTML: https://iconotheca.com/study/private-sales-versus-auction/ ## Key points - By the Art Basel and UBS estimates for 2025, dealer and private-treaty sales account for roughly two thirds of global art market value and produce no public price. - Christie's reported that its three largest sales of 2025 were made privately, none of which has a published figure, while the largest public transaction of the year is documented to the dollar. - Private channel volume rises when the public channel falls: in 2024 public auction sales fell 25 per cent while private sales by auction houses rose 14 per cent. - Repeat-sales indices are built only on works that came back to auction, which excludes both ends of the return distribution and every work that went to a museum or a dealer instead. ## The measured market is mostly not an auction ## The houses' own numbers say the same thing more sharply ## The private channel moves against the public one ## What an index can and cannot see ## What 'sold privately' in a provenance actually tells you The visible market is a sample, and it is not a random one. It over-represents works whose owners were willing to test them in public, under-represents everything that failed or never came back, and excludes by construction the transactions the trade itself regards as the largest of the year. This does not make auction data worthless; it is the only continuous transactional record the field has, and it should be used. It makes the qualifier compulsory. When an index, a valuation or a catalogue essay reports what the market did, the honest sentence names the channel it measured, and the honest provenance line for a private acquisition records a year, an intermediary and the absence of a price rather than a number nobody can check. ## Questions **Why would a seller accept a private sale price below what a public sale might reach?** Because the comparison is not between a private price and a good auction result, it is between a private price and the distribution of possible auction outcomes including failure. A bought-in lot is publicly marked and is harder to sell for years afterwards. Private treaty converts an uncertain outcome into a certain one, and sellers of major works price that certainty. **Do the auction houses' published private sales figures capture the whole private market?** No. They capture private treaty conducted by the houses themselves, reported at just under $4.2bn globally for 2025 in the Art Basel and UBS estimates. Dealer sales, estimated separately at $34.8bn, are a far larger private channel, and both figures are survey-based estimates rather than counts of transactions. **Can a private sale price ever be verified independently?** Rarely, and usually only when litigation, an estate filing, a museum accession record or a lender's disclosure forces it into the open. Absent one of those, a reported private price rests on the willingness of one party or an intermediary to describe it, which is a weaker foundation than a hammer price and should be cited as such. **How should a provenance record a private acquisition?** With the channel, the year, the intermediary if known, and an explicit statement that no price is documented. Naming the dealer or agent is more useful than naming a figure, because the intermediary can sometimes be traced through stock books, shipping records or exhibition loans, whereas an unsourced price simply propagates. ## Sources - [1] Art Basel and UBS, 'Global sales rise 4% to $59.6 billion in 2025, amid ongoing market recalibration', on the Art Basel and UBS Global Art Market Report 2026 by Arts Economics (Clare McAndrew), March 2026. - [2] Arts Economics, 'The Global Market', The Art Basel and UBS Art Market Report 2025 (2024 figures). - [3] Kabir Jhala, 'Christie's and Sotheby's end 2025 with increased sales, thanks to luxury goods, trophy lots and private deals', The Art Newspaper, 17 December 2025. - [4] Sotheby's, 'Historic Night at Sotheby's Continues as White-Glove Leonard A. Lauder Collection Totals $527.5m', press release, 18 November 2025. - [5] The Value, 'At US$236.3m, Klimt's Portrait of Elisabeth Lederer becomes the second most expensive work ever auctioned', November 2025, giving the hammer price of US$205,000,000 and the premium-inclusive US$236,360,000. - [6] Orley Ashenfelter and Kathryn Graddy, 'Art Auctions: A Survey of Empirical Studies', NBER Working Paper 8997, June 2002, on selection bias in art price indices and sale rates by department. - [7] Sotheby's, 'Private Sale Conditions of Business for Buyers'. - [8] Anna Brady, 'Auction houses made significant recoveries in 2026, ArtTactic report finds', The Art Newspaper, 10 July 2026. - [9] 'Interchange (de Kooning)', Wikipedia. Tertiary source, cited only for the reported 2015 private sale figures; these should be replaced with a primary record if one is ever produced.