More bidders and more lots selling above their estimates helped make 2025 the year of single-collection sales, according to the HENI Auction Index.
Works collected over decades by names such as cosmetics heir Leonard Lauder and Hyatt Hotel's co-founder Jay Pritzker and his wife Cindy generated nearly $1.6 billion for Sotheby’s and Christie’s last year.
The sales, where all the lots come from just one collection, rated a B+ on the index up from a C- the previous two years.
Also among them was a major sale of surrealist work at Sotheby's in New York in November reportedly collected by the late music mogul Nesuhi Ertegun and his wife Selma which included Frida Kahlo's El sueño (La cama) which sold for $54.7 million setting a new auction record for a female artist.
The index, which used more than 10 different metrics to gauge success, found the percentages of lots hammering above low and high estimates were both almost 10 percentage points above average over the past decade.
It also found the average number of bidders per lot rebounded from 2.7 in 2024 to 3.1 in 2025, back in line with the average over the past decade.
Read our full analysis here.