Brevan Howard's flagship $26.5 billion hedge fund made its first monthly profit this year in July, as it tries to avoid posting a first-ever year of losses.

The Brevan Howard Master Fund, run by Alan Howard and one of the world's biggest hedge fund portfolios, posted an estimated 0.7% gain in July, according to a letter to investors reviewed by The Wall Street Journal. After six consecutive monthly losses, this trims the year-to-date loss at Brevan's flagship fund to 3.7% to the end of July.