While much of the global auction market continues to be in a correction period, overall auction sales at Christie’s, Sotheby’s and Phillips for the first half of 2025 have fallen only 6.2 percent and the number of lots sold rose 1.3 percent compared to the same time last year.“Nothing has felt very good this year, but the data actually showed the decline was 6.2 percent compared to the level of uncertainty, especially due to things like the tariffs,” Lindsay Dewar, ArtTactic’s chief operating officer and head of analytics, told ARTnews.The art market research and analysis company ArtTactic released five reports earlier this week with detailed analysis of global auction data, including online-only sales, geographic trends, category breakdowns, luxury goods, and the impact of guarantees. While global auction sales fell 6.2 percent overall, sales of post-war and contemporary art dropped 19.3 percent to $1.22 billion, impressionist and modern art fell 7.7 percent to $989.5 million, and luxury sales were almost flat (down 0.5 percent to $805.9 million). There were big increases for design, decorative arts and furniture (up 20.4 percent to $172 million) and even more for Old Masters (up 35.6 percent to $171.2 million).Global auction sales for the first half of the year of 2025 were 6.2 percent lower compared to the same period last year, but the second lowest for the past decade. Chart courtesy of ArtTactic.Dewar noted the drop in sales of post-war and contemporary art for the first half of 2025 was due to fewer high-priced trophy lots, noting the withdrawal of Andy Warhol’s Big Electric Chair and Alberto Giacometti’s bronze bust Grande tête mince (Grande tête de Diego) which failed to find a buyer in May. “If you’ve got a real trophy lot, and you’re a bit anxious about selling it at the moment, I imagine a lot of people, if they didn’t have to sell, they would hold on to it,” she said. “It’s those kind of bellwether blue chip artists that people trade in when people get nervous and don’t want to sell them. There might be things selling between $1 and $10 million, but that’s not going to really pull the totals up.”By comparison, the 7.7 percent drop in total sales of impressionist and modern art reflects a more conservative, risk-averse approach to new acquisitions by buyers, according to Dewar. “It’s people thinking in an uncertain market, if I have, say, a million dollars to spend, am I going to spend it on an artist that I didn’t hear of until a month ago?,” Dewar said. “Or am I going to spend it on an artist that has been around for the last 50 years, whose market trades very consistently? You might not get a huge return, but it will still be worth probably around $1 million in two or three years.”Data analyzed by ArtTactic also showed the outsize role of guarantees on artworks by postwar and contemporary artists born after 1910 at evening sales in New York, London, and Hong Kong.For the first half of 2025, the percentage of guaranteed post-war and contemporary works sold at evening sales has risen to 72.9 percent, the highest market share since 2016. Chart courtesy of ArtTactic.For the first half of 2025, the market share of post-war and contemporary works sold at evening sales with either a house or third-party guarantee rose to 72.9 percent, the highest number since ArtTactic started tracking this figure in 2016. “This is probably the highest level of guarantees ever on the market,” Dewar said. “Some people will argue this is a sign of market confidence. People are saying that, but I think that actually, at the moment, it’s a sign of risk aversion.”Third-party guarantees also accounted for 96 percent of total guaranteed sales value and 90.7 percent of guaranteed lots sold for works in this category, as auction houses transferred the risk of guaranteeing to third-parties. “It’s so unusual now to see something that isn’t,” Dewar said, noting the shift even applies to dedicated single owner sales, and essentially means those lots have been sold before the auction takes place. “It’s essentially a public-private sale, you could argue. It does just take a bit of the risk out for people.”Data also showed lots without guarantees often didn’t sell or withdrawn pretty quickly. “No one would guarantee that Giacometti because there was no buyer for it at the $70 million level that the client wanted, and therefore it did not sell,” Dewar noted. “So without the guarantee, how do you know if a lot is is going to sell or not?”One upside for the small number of works without guarantees that do sell at auction is the much higher average compounded annual growth rate (CAGR) of 36.4 percent, compared to an average of 4.6 percent for lots with guarantees.For the first six months of 2025, auction lots which did not have guarantees had a 36.4 percent compound annual growth rate (CAGR). Lots with guarantees had a CAGR of 4.6 percent. Chart courtesy of ArtTactic. While non-guarantee lots can be more volatile, Dewar said the likelihood of a better return is due to a perception that guarantees can be a kind of a hedge against risk, and might discourage more bidding. “So if you are able to not need the guarantee, you can perform so much, so much better, especially in a market like right now,” she said.Dewar also noted the emphasis on sales based in New York, compared to auctions in other cities like Paris, London, or Hong Kong, and a shift in the summer sales calendar at Christie’s, Sotheby’s and Phillips. “There really used to be a big summer season,” Dewar said, noting Christie’s did not have an evening sale and “much, much smaller sales” at Sotheby’s and Phillips. “It felt like they were holding back a little bit. I get the feeling that it’s a supply issue, and they were wanting to hold back and wait for October.”Data analysis by ArtTactic showed online-only auctions experienced a 10 percent drop in value, but the number of lots sold through these platforms grew by 12.9 percent, with “evolving buyer engagement” and growth “largely centred in major European cities”.Dewar attributed these shifts to greater confidence in buying and selling online over the last five years prompted by the Covid-19 pandemic.“Covid allowed people to be like, Oh, actually, okay, this is fine. We can trade online. We can buy something for a million dollars online, or whatever. So people are confident to do it.”In addition to the lower-end of the market—works estimated at $1 million and below—also doing well, Dewar noted the structure of online sales allowing for more bids over a week compared to a day sale. “It just allows more volume to go through that particular sales channel,” she said.For the second half of the year, Dewar anticipates that guarantees will play a “really crucial role” in attracting consignments. “It gives them confidence that the auction house is confident in them, and it helps kind of with a bit of risk aversion,” she said. The perception of guarantees in the art market might also shift due to their prevalence and examples of success, such as the recent record-breaking sale of a Venice view by Canaletto for £31.9 million ($43.7 million) at Christie’s Old Master’s auction in London. “I think that the role of guarantees could be about to turn from being a risk aversion tactic to a confidence marker,” Dewar said. “If nearly three quarters of the market is guaranteed, and you’re looking at one lot that isn’t, I think I would be starting to think ‘now, well, why didn’t they guarantee that one? Are they so confident that it’s such an amazing lot or or does nobody else want it?'”