The auction houses make money by charging a fee on both sides of every sale: a buyer's premium added on top of the hammer price, and a seller's commission taken out of the consignor's proceeds. On a mid-market lot, the house's gross take typically runs 25% to 35% of the hammer price. That is the part most people see. The bigger story is everything around it. The Big Three now pull billions more from private sales, art-backed lending, luxury goods, and the business of guaranteeing an outcome before the gavel falls. We pay close attention to all of it, because these incentives shape which works get sold, how they get priced, and who is left holding the risk when a market turns.

How much of an auction sale do the houses keep in fees?

Every winning bidder at a major auction pays more than the hammer price. The extra charge is called the buyer's premium, and it is the single biggest source of auction house income.

The rates are tiered. At Christie's, following a September 2025 increase, buyers pay 27% on the first $1.5 million of hammer price, 22% on the portion between $1.5 million and $8 million, and 15% above that. Sotheby's matches Christie's almost exactly after reverting its fee structure in early 2025: 27% up to $1 million, 22% from $1 million to $8 million, and 15% beyond. Phillips carries the steepest base rate at 29% for lots under $1 million, though it offers a "priority bid" discount (25% instead of 29%) to collectors who place written bids at least 48 hours before a sale.

The math adds up quickly. Imagine you win a painting that hammers at $1 million. At Christie's or Sotheby's you owe $270,000 in premium alone. At Phillips without the early-bird discount, the same hammer price costs you $290,000 extra. On a $10 million lot, the blended premium at Christie's comes to roughly $1.7 million.

These rates have crept upward for decades. Christie's raised its premium three times in under three years leading into 2025. The pattern is consistent. As competition for top consignments drives seller commissions down, the houses move the cost onto buyers.

How much commission do sellers pay at auction?

Consignors pay their own fee, and the rate is far less predictable than the buyer's side. Buyer premiums are published. Seller commissions are negotiated deal by deal, and the bigger the lot, the smaller the cut.

For everyday material, a seller might pay 10% to 15% of the hammer price. For trophy lots worth tens of millions, the commission can shrink to zero. Houses will waive the seller's fee entirely to win a headline consignment, banking instead on the buyer's premium and the publicity the sale brings.

Sotheby's tried to reshape this model in early 2024, rolling out a flat 10% seller's commission for works estimated up to $5 million paired with a slashed buyer's premium. The idea was to make pricing clearer. It backfired. Sellers found the structure less attractive, and by late 2024 Sotheby's reversed course, returning to tiered buyer's premiums and flexible seller terms.

There is a lesson here for investors. Published fee schedules tell you what buyers pay and only hint at what sellers keep. Two identical works sold at the same house on the same night can carry very different commission arrangements. We model this every time we underwrite a potential exit, because the headline rate is rarely the real one.

What is a third-party guarantee, and why does it matter?

Guarantees have become the most discussed financial tool in the auction business. A guarantee is a minimum price promised to the seller before a lot goes to auction. If bidding fails to reach that floor, the house (or a third party) buys the work at the guaranteed amount.

There are two kinds. A house guarantee means the auction house puts its own money on the line. A third-party guarantee (also called an irrevocable bid) shifts that risk to an outside backer, often a dealer, collector, or fund. The backer agrees in writing to buy the lot at a set price if no one else bids higher. In return, the guarantor gets a financing fee or a cut of the buyer's premium, typically if the lot sells to someone else. If bidding exceeds the guaranteed price, the guarantor may also receive 15% to 20% of the upside, according to industry insiders.

So picture the incentives. Imagine you agree to guarantee a painting at $8 million. If nobody outbids you, you own a work you were willing to pay $8 million for anyway. If the room runs it to $12 million, you collect a slice of the difference and walk away owning nothing. You have written what amounts to a put option on the painting, and you get paid the premium either way. Sellers get certainty. The house locks down a marquee consignment. The guarantor gets a risk-adjusted return with an informational edge: they know the reserve price, the lowest level the seller will accept.

That edge is also the core problem. Guarantors know the reserve. They often know the auction house staff personally, because most are also clients. Critics argue this creates a two-tier market where connected insiders bid with better information than everyone else in the room. Some observers note that heavily guaranteed sales can lose competitive energy, with other bidders sensing that lots are already spoken for.

The financial risks are real. In autumn 2008, Sotheby's reportedly lost $52 million in a single season from house guarantees that went wrong. The houses have since shifted most guarantee risk to third parties. The practice remains a flashpoint for anyone who cares about price transparency in the art market. We count ourselves in that group.

How big is the private sales business for auction houses?

Not everything goes through the saleroom. Private sales, where the house brokers a deal between buyer and seller without a public auction, have grown into a large business line.

Christie's recorded roughly $1.5 billion in private sales during 2025, up from about $800 million in 2019. Sotheby's private sales hit $1.2 billion in 2025. Together, private transactions now account for 15% to 20% of each house's total volume.

The appeal for the houses is straightforward. Private sales carry fewer overhead costs than staging a live auction, and the commission rate can be higher because sellers value discretion. For sellers, a private deal avoids the public risk of a work failing to sell (a "buy-in" in auction language), which can damage an artist's market.

Here is why this matters for anyone tracking the art market as an asset class. These transactions are opaque. They do not appear in public auction records, which means the price indices and market data that many investors rely on capture only part of the picture. When we build our own index, we work the same way Robert Shiller built the Case-Shiller home price index, tracking the same work across repeated sales. Every private deal that stays off the record is a data point the whole market is flying blind on.

Why are auction houses selling handbags, watches, and wine?

Fine art still anchors the business. Luxury goods have become a critical growth category. Handbags, watches, wine, jewelry, and collectible cars now fill a roughly $3 billion hole left by softening high-end art sales in recent years, according to ARTnews reporting.

Christie's luxury division topped $1 billion in global sales during 2025 (excluding private sales), with a 90% sell-through rate. Luxury goods made up 22% of Christie's first-half 2025 total. At Sotheby's, luxury turnover rose 22% year-on-year to $2.7 billion.

The shift has strategic value beyond revenue. Christie's reports that luxury categories recruited 41% of its new buyers, many of whom later buy across other categories including fine art. Lower price points on watches and handbags draw younger collectors who may grow into serious art buyers. The houses are buying the top of a funnel. A first watch purchase at 30 becomes a first painting purchase at 45.

How do auction houses make money lending against art?

Sotheby's Financial Services runs what amounts to a specialty lending operation. Collectors borrow against the appraised value of their art, typically at loan-to-value ratios of 50% to 60%, without selling the work.

The division hit a record portfolio balance above $1.8 billion in 2025. In January 2026, Sotheby's completed a $900 million securitization, packaging art-secured and (for the first time) collectible-car-secured loans into notes sold to institutional investors. The transaction was significantly oversubscribed, signaling strong appetite from bond markets for art-backed debt. Over its five-year partnership with Alexander Klabin and Ancient, Sotheby's Financial Services grew its portfolio by more than $1 billion and tripled its profitability.

For art investors, this matters in two ways. First, lending generates steady fee income that is far less volatile than auction commissions, giving the house a financial cushion during a downturn. We have always thought the most durable parts of this industry are the recurring-revenue parts, and a loan book is about as recurring as it gets. Second, the growth of art-backed lending expands the pool of capital treating art as a financial asset. When bond investors are willing to buy notes backed by paintings, the market is telling you something about how seriously it now takes art as collateral. Over time we believe that supports price levels across the asset class.

What did the auction houses earn in 2025?

The Big Three posted a combined $14.1 billion in sales for 2025, up roughly 10% from 2024. The recovery is real. It is also uneven, and worth being precise about.

Sotheby's led with $7.1 billion in consolidated sales (up 18%) and $1.4 billion in revenue (up 21%). Fine art rose 15% to $4.3 billion. Those top-line numbers sit on top of a difficult balance sheet. Sotheby's reported a $248 million pretax loss for fiscal 2024, more than double the prior year, driven by falling commission income, rising severance costs ($29.2 million, up from $11.4 million), and the debt load from Patrick Drahi's 2019 leveraged buyout. An August 2024 capital injection from Abu Dhabi sovereign wealth fund ADQ, worth $909 million for a 24% stake, gave the company breathing room.

Christie's posted $6.2 billion in total sales (up 6%), with public auctions at $4.7 billion (up 8%) and luxury goods at $795 million (up 17%).

Phillips reported $927 million in total sales (up 10%), holding its position as the smallest of the three while growing at a competitive clip.

We would read these results with some caution. Asian sales still lag. The market remains concentrated in trophy lots while the mid-market stays soft. And a meaningful share of the growth came from raising fees and from luxury goods rather than from a broad rebound in art buying. The houses are healthier than they were. The art market underneath them has further to recover.

What do auction house economics mean for art investors?

Auction house fee structures directly affect net returns on art. Imagine you buy a work at a $500,000 hammer price and pay a 27% premium. You start with a cost basis of $635,000, which is $135,000 above the hammer before you have paid a single dollar of seller's commission on the way out. To break even on exit, the work has to appreciate enough to clear that round trip first. These are not abstract numbers. They are the difference between a good entry price and a poor one.

The guarantee system shapes pricing in ways that can help or hurt investors. A guarantee sets a floor, which can support an artist's market. It can also inflate a reported sale price if the guarantor's financing fee gets baked into the final number, which leaves a misleading signal sitting in the public auction record. When we read comps, we try to strip that noise out.

The growth of private sales compounds the problem. The public auction data investors use for valuation now captures a shrinking share of total transactions. Artnet, Art Basel, and other market reports acknowledge this gap and cannot fully close it. We built our dataset the hard way, by recording roughly 150,000 individual transactions ourselves, precisely because the public record is incomplete.

The push into lending and luxury goods shows where the houses see their future: less dependent on the unpredictable cycle of blockbuster consignments, more focused on recurring fee income and a broader collector base. We think that is a rational read of their own business, and a useful tell for anyone investing in art through any channel. Watch where the houses put their capital. It tells you where they think the durable money is.

The Bottom Line

  • Christie's, Sotheby's, and Phillips earn 25% to 35% of hammer price on mid-market lots through combined buyer premiums and seller commissions, though the effective rate drops below 15% on trophy works.
  • Third-party guarantees have shifted sale risk from houses to outside backers, but they create information gaps that benefit guarantors over regular bidders.
  • Private sales now account for $1.2 billion to $1.5 billion per house annually, and these transactions do not appear in public auction records that investors use for pricing.
  • Luxury goods (watches, handbags, jewelry, wine) contributed over $3.5 billion across the Big Three in 2025, recruiting new buyers and offsetting softness in high-end art.
  • Sotheby's Financial Services holds a record $1.8 billion art-lending portfolio, and the securitization of art-backed loans signals growing institutional acceptance of art as collateral.
  • Transaction costs matter: at current premium levels, a $500,000 purchase carries $135,000 in buyer's premium alone before any seller-side fees on exit.

Sources

  1. The Art Newspaper. "Sotheby's hikes buyer's premiums as auction houses test new fee structures." February 2026. https://www.theartnewspaper.com/2026/02/17/sothebys-adjusts-buyers-premiums-fee-structures-securitisation
  2. The Art Newspaper. "Christie's and Sotheby's end 2025 with increased sales, thanks to luxury goods, trophy lots and private deals." December 2025. https://www.theartnewspaper.com/2025/12/17/christies-and-sothebys-end-2025-with-increased-sales-thanks-to-luxury-goods-trophy-lots-and-private-deals
  3. Artnet News. "Christie's, Sotheby's Report Increases in Annual Sales: Good News for Market Watchers." December 2025. https://news.artnet.com/market/christies-2025-sales-results-uptick-2730928
  4. South China Morning Post. "Big 3 auction houses report uptick in 2025 revenue, but Asia still lagging." December 2025. https://www.scmp.com/lifestyle/arts/article/3337313/big-3-auction-houses-report-uptick-2025-revenue-asia-still-lagging
  5. Artlyst. "Sotheby's Financials 2025: Sales and Revenue Insights." December 2025. https://artlyst.com/sothebys-reports-7-1-billion-in-consolidated-sales-for-2025/
  6. Sotheby's. "Sotheby's Projects 2025 Consolidated Sales of $7 Billion." Press Release, 2025. https://www.sothebys.com/en/articles/sothebys-projects-2025-consolidated-sales-of-7-billion
  7. Irish Times. "Sotheby's annual loss more than doubles to $248m." September 2025. https://www.irishtimes.com/business/2025/09/11/sothebys-annual-loss-more-than-doubles-to-248m/
  8. Artnet News. "Why Phillips's New Fee Structure Could Fall Flat." 2025. https://news.artnet.com/market/priority-bidding-phillips-2671429
  9. Puck. "The New Phillips Fee Structure, Explained." 2025. https://puck.news/the-new-phillips-fee-structure-explained/
  10. ARTnews. "Auction Houses Are Plugging the $3 B. Gap Left by Tanking Art Sales with Luxury Proceeds." 2025. https://www.artnews.com/art-news/market/christies-sothebys-auction-houses-luxury-fashion-art-1234749341/
  11. ARTnews. "Christie's Reports $2.1 B. Sales for 2025 So Far, With Luxury Items Generating Nearly a Quarter of Total." 2025. https://www.artnews.com/art-news/news/christies-h1-2025-auction-sales-report-1234747544/
  12. Apollo Magazine. "Handle with care: the problem with auction guarantees." 2025. https://apollo-magazine.com/auction-guarantees-irrevocable-bids-risks-christies-sothebys-phillips/
  13. Center for Art Law. "Secrecies, Guarantees, and Securities in the World of Auction Houses." 2025. https://itsartlaw.org/art-law/secrecies-guarantees-and-securities-in-the-world-of-auction-houses/