The International Monetary Fund (IMF) has called for closer monitoring of hedge funds' use of leverage after highlighting that the sector has more than tripled in size over the past decade, according to a report by Reuters.

The IMF said hedge fund assets had reached approximately $13tn in early 2026, compared with around $4tn in 2013. The expansion has increased the industry's role in trading, market liquidity and the transfer of risk between financial institutions.

Much of the growth has been driven by leverage, including synthetic leverage created through derivatives, according to the IMF. The organisation warned that while hedge funds can improve market efficiency and provide liquidity, their leveraged positions can also amplify market stress when conditions deteriorate.

The funds have also become increasingly significant participants in sovereign debt markets, particularly US Treasuries. Hedge funds now account for around 9% of the Treasury market, more than double their estimated 4% share in 2022.

The IMF said the growing presence of hedge funds in bond markets can support liquidity and price discovery during normal conditions, but their ability to take on substantial risk may increase the potential for abrupt market dislocations during periods of stress.

A key concern for regulators is the limited visibility into hedge fund positions and exposures. The IMF described the industry as inherently opaque and said gaps in available data make it difficult for policymakers to assess the risks building up across the sector.

The organisation is calling for improvements in data collection and risk monitoring to help regulators identify potential vulnerabilities associated with hedge fund leverage and interconnectedness with the wider financial system.

The findings form part of a chapter of the IMF's forthcoming Global Financial Stability Report, due to be published in full on October 13.