Billionaire Chris Rokos’s macro hedge fund had its best month ever, gaining 14% in March amid market chaos fueled by the coronavirus pandemic.

That takes the fund’s advance for the year to about 20%, according to a person with knowledge of the matter. About a quarter of this year’s returns have come from short equities trades as the longest-running bull market in stocks came to an end, said the person, who asked not to be identified because the information is private.

A significant part of the gains came from options trades that Rokos placed in the second half of last year, the person said. The wager was linked to the firm’s view that the U.S. economy was headed for a recession and the Federal Reserve would have to cut interest rates to near zero. While the firm did not predict the pandemic, the trades paid off as coronavirus threatened to tip the global economy into recession and sparked rate cuts in the U.S.

A spokesperson for London-based Rokos Capital Management declined to comment.

The returns extend a winning streak for the fund, which rose 9.3% last year, its biggest annual gain since 2016. The hedge fund benefited from a change of structure last year, with Rokos merging portfolios previously run by individual traders into a single pool of money, allowing him to place bigger bets.

Macro hedge funds, which spot economic trends to bet across asset classes, are finding opportunities in the recent market volatility after years of lackluster returns. Overall, such funds were about flat in March and down 0.8% for the year, the best returns among the five main strategies tracked by Bloomberg.

Brevan Howard Asset Management’s flagship hedge fund posted its best monthly gain in March, jumping about 18%, according to people familiar with the performance. A fund run by Gemsstock Ltd. also soared last month.

Read more: Brevan Howard Rebound Fueled by Trader Golchin’s 41% Return

Prior to setting out on his own, Rokos was a co-founder of Brevan Howard and made $4 billion for that firm from 2004 to 2012. Rokos Capital Management’s assets have jumped to more than $9 billion from $3.5 billion in 2016, its first full year of trading.

This article was provided by Bloomberg News.