The recent market turmoil has taken Bill Ackman’s Pershing Square hedge fund into the red for 2015, the investor said in a letter on Wednesday.

Pershing Square had been up 10 percent for the year through July but “dramatic downward market volatility” erased the gains, leaving the fund with a loss through Aug. 25, according to the semi-annual letter.

Ackman did not specify how large a loss Pershing racked up, but said it was less than the broader market.

The S&P 500 was down 9.3 percent through Aug. 25.

Ackman said the fund has not made “meaningful” changes to the portfolio as it doesn’t hedge short-term market declines and isn’t forced to sell because it doesn’t use margin leverage.