Billionaire John Paulson’s merger strategy has gained 10 percent this year lifted by consolidation among drugmakers.

The $19.3 billion New York-based firm posted a 0.7 percent return last month in a merger fund that uses leverage to amplify gains, according to three people familiar with the matter, who asked not to be identified because the information is private. An unlevered version rose 0.3 in March and is up 4.5 percent this year.

The firm’s merger strategy is its oldest and largest, with $10.1 billion, one of the people said. The funds have been a bright spot for Paulson & Co. in recent years, growing from $7 billion at the start of 2014, as some wagers on the U.S. recovery, gold and Europe caused losses that spurred withdrawals.

The firm’s assets have declined from a peak of $38 billion in 2011. Paulson & Co. has reduced the minimum investment commitment that new investors must make to $5 million from $10 million for most of its funds, according to a regulatory filing last month.

Armel Leslie, a spokesman for Paulson & Co. with Peppercomm, declined to comment on the returns.

Valeant Takeover

Valeant Pharmaceuticals International Inc.’s takeover of Salix Pharmaceuticals Ltd., of which Paulson & Co. was the largest shareholder as of Dec. 31, helped drive this year’s performance.

Paulson & Co. bought Salix shares at an average price of $105, the person said. Last month, the drugmaker accepted a sweetened $173-a-share offer from Valeant after Endo International Plc. made a competing bid.

Other Paulson strategies had mixed performance. His credit fund and event-driven Advantage fund were little changed in March, the people said. The credit fund is up 2.9 percent this year and the Advantage fund, which bets on companies undergoing events such as bankruptcies or spinoffs, rose 1.8 percent in 2015.

The firm’s special situations fund fell 2.4 percent in March and has lost 4.8 percent this year, according to the people. Gains from investments in mortgage servicers and post- reorganization equities were offset by losses on Greek financials and utilities positions, one of the people said.