Last May, three Chinese buyers spent $116 million in one night at a Sotheby's art auction.
Chinese property company Dalian Wanda Group shelled out $20.4 million for one of Monet's masterpieces: "Bassin aux nympheas les rosiers." Chinese media mogul Wang Zhongjun paid $29.9 million for Picasso's "Femme au Chignon un Fauteuil," while an unknown Chinese buyer paid $66.3 million for Van Gogh's "L'allee des Alyscamps."
Commenting on their big-money Monet, Dalian Wanda's art chief told CNBC: "I think that it's decently priced."
What counts as a "decent price" for Chinese art collectors, however, may be changing. With Chinese stocks in a tailspin and China's economy slowing, the Chinese rich have lost billions of dollars in paper wealth over the past two months. Now art market experts are wondering if China's stock slide could also spill over into the broader $50 billion-a-year global art market, which has seen a string of record prices driven in part by Chinese demand.
"I think there will definitely be an impact," said Ken Yeh, director at Acquavella Galleries and former chairman of Christie's Asia. "Chinese collectors have become a very important part of the market."
Even before China's recent stock-market slide, there were signs that some Chinese collectors were paring back their spending. According to Artnet, total art sales in China and Hong Kong fell 30 percent in the first half of 2015 to $1.5 billion from $2.2 billion.
During the spring sales in Hong Kong, "I heard many dealers talking about how weak the sales were. It's definitely down," Yeh said.
So far, the China-effect has largely been confined to the local art market in China—buyers of Chinese art sold in mainland China and Hong Kong. Demand among Chinese buyers for higher-priced trophy works by Western artists at the London and New York sales has so far shown few signs of trouble.
Christie's said that mainland Chinese buyers have increased their spending on global art by 47 percent in the first half of 2015. Sotheby's said that Chinese buyers spent 51 percent more during its summer sales in London and that Asian buyers competed for 30 percent of the lots offered at its spring evening sale.
Suzanne Gyorgy, managing director and global head of the Art Advisory & Finance Group at Citi Private Bank, said the super-rich Chinese who collect the trophy Picassos and Monets are less affected by gyrations in the economy and stock market since they have such a larger wealth cushion.
"The clients we work with have plenty of liquidity and they're not as affected," she said.
She added that the tastes of Chinese collectors have also shifted toward Western art and away from Chinese art—so the weakness in Chinese art sales may not signal future weakness in New York and London.
While some market watchers are drawing comparisons to the Japan-led art boom of the late 1980s, which crashed with the Japanese property market in 1990, others say today's art market is far more diverse and durable. Even if the Chinese collectors put down their bidding paddles, buyers from the U.S., Middle East and Europe will step up in their place.
"In the late 1980s, the market was so much smaller," Gyorgy said. "The Japanese were just about the only ones buying. Now we're working with collectors in Asia, Latin America, the U.S., Europe and so if one segment goes away, another segment comes back."
Yet the big test for the market will be in October and November, during the fall sales in Hong Kong and New York. Last fall, Sotheby's and Christie's sold $1.78 billion worth of art, with many of the bids coming from Chinese buyers.
Gyorgy said all it takes is one weak auction to damage the already fragile confidence of Chinese buyers.
"Everyone is going to be watching this very closely," she said. "Art is as much a psychological market as a financial one. If there is one sale that isn't strong, people get spooked."