Quant hedge funds recovered from October’s shaky start — except for one big name that suffered serious losses

• Renaissance Technologies has lost money in its two public funds for the year after a rough October.
• Quants started October on a losing streak but, on average, recovered by the end of the month.
• Early October felt similar to the summer troubles that stung many big-name quants.

October felt like summer for many quants — at first.

Last month started with one of the worst four-day trading periods on record for computer-run hedge funds, according to a Goldman Sachs client note, which said the average quant fund lost 1.8% through October’s first week.

For many quants, the painful start of October brought back memories of June and July, when systematic funds were slammed due to crowded trades, a momentum sell-off, and artificially inflated junk stocks.

Indeed, in the first week of October, Renaissance Technologies — the legendary quant firm founded by the late billionaire Jim Simons — had given away all of its gains on the year in its two biggest funds for external investors. According to HSBC’s Hedge Weekly report, the two funds finished the month in the red for the year.

Renaissance’s Institutional Equities fund was down more than 14% in October, and the strategy’s 2025 losses stand at 8.3%. The Diversified Alpha strategy lost more than 15% last month, putting its year-to-date losses at 10.5%.

Renaissance Technologies declined to comment.

Meanwhile, Paris-based Capital Fund Management’s two largest funds — Stratus and Discus — also lost money in October; the pair were down 1.3% and 2.9%, respectively, for the month, but still positive for the year at 6.5% and 1.2%, a person close to the firm told Business Insider.

Like this summer, the tides eventually turned in October for most funds. A Goldman note from the end of the month states that the last four days of trading in October were positive for quants, helping the average systematic fund finish the month flat.

Despite 2025’s choppiness, Goldman said, stock-trading quants are up 13% year-to-date.

Engineer’s Gate ended October slightly positive, gaining about 0.6%, putting its year-to-date gain at roughly 5.5%, two people familiar with the firm’s performance said. Qube’s flagship strategy was up 1.4% last month, according to a person close to the $34 billion London-based manager. The fund’s year-to-date figures are not known, and the firm declined to provide them.

Man Group’s Numeric Quantitative Alpha fund was flat for the month and is up more than 16% year-to-date. Marshall Wace’s TOPS fund reportedly returned 1.2% in October and has made close to 15% this year so far.

$9.4 billion Walleye’s quant portfolios were the biggest contributors to the firm’s 0.8% gain in October, the firm told investors in a monthly update, with “strength in Asia offsetting weakness in US exposures.”