What a difference a quarter made for many hedge funds — but especially for Stephen Mandel Jr.’s Lone Pine Capital.

The Tiger Cub was flying high in the first half of the year after the long-short fund surged 51 percent and the long-only fund jumped 50 percent in the second quarter.

But in the third quarter, the long-short fund lost 31 percent, including about 25 percent in July, according to an investor. As a result, it finished the period flat for the year, an investor says. The long-only fund fared only a little better, dropping 23 percent in the third quarter but remaining up 6 percent for the year.

Oher Tiger-related funds, and others that emphasize the market’s high-flying AI-related stocks, suffered similar — though less painful — fates in the third quarter.

Lone Pine currently manages between $18 billion and $19 billion. Two-thirds to three-quarters of capital is in the long fund, and roughly 80 percent is invested in the U.S. The performance disparity between the two funds suggests Lone Pine’s shorts fared a little worse than the longs.

Interestingly, as Institutional Investor previously reported, Lone Pine aggressively shook up its portfolio in the second quarter, when the long-short and long-only funds surged 51 percent and 50 percent, respectively. By the end of the period, five of the seven largest U.S.-listed long positions had been newly established that quarter. Altogether, the seven biggest longs accounted for roughly 40 percent of the U.S. portfolio.

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The largest U.S.-listed long at the end of June was Nebius Group, a Dutch provider of artificial intelligence infrastructure, after the hedge fund bought a new stake of nearly 4.3 million shares valued at $1.176 billion, representing 7.2 percent of the U.S. portfolio. Like many AI stocks, Nebius lost nearly one-third of its value in July after peaking at the end of June. It has since rebounded, but was still down nearly 15 percent in the third quarter.

Lone Pine also established a new position in data storage company Seagate Technology, making it the firm’s third-biggest U.S.-listed long, and took a new stake in semiconductor equipment giant Applied Materials, which became the No. 5 long. The stocks were down 4.5 and 29 percent, respectively, in the third quarter.

Lone Pine made new non-tech-related bets as well, on home improvement retailing giant Home Depot and Germany-based Linde, a large industrial gas supplier. 

The hedge fund made at least three significant sales in the second quarter.

It fully unloaded its stake in Vistra Corp., a retail electricity and power generation company that was Lone Pine’s largest U.S. long at the end of the first quarter. It liquidated its position in Talen Energy, an independent power producer and infrastructure company and previously the No. 6 long. And it sold its investment in Clariant, a Swiss specialty chemicals company that was its 12th-largest long.

Other Tiger-related funds suffered sizable losses in the third quarter.

Robert Citrone’s Discovery Capital Management dropped about 10 percent but is still up 16.8 percent for the year — better than the Nasdaq Composite’s 15.6 percent in 2026. Discovery looks for macro and fundamental fund mining opportunities in both developed and developing markets.

Philippe Laffont’s Coatue Management lost half of its first-half gain in the third quarter, finishing the period up just over 12 percent. 

Light Street Capital Management’s long-short fund dropped more than 50 percent of its first-half gain of 37 percent-plus, finishing the third quarter up 15.7 percent. Glen Kacher’s long-only fund climbed 26.75 percent through the end of September after posting a 40 percent gain in the first half.

Chris Hansen’s Valiant Capital Management is up just 1.42 percent for the year after posting double-digit losses in both July and August. And smallish Flight Deck Capital, which added nearly 119 percent through June, finished the third quarter up a strong 80 percent despite making money in both August and Septembe[WM(1] r. However, the fund headed by Jay Kahn lost 25 percent in July.