Asian hedge fund firms are pouring hundreds of millions of dollars into private investments as they seek higher returns, muscling into an area that has long been the preserve of private equity and venture capital.

Aspex Management, Tybourne Capital Management, Anatole Investment Management and Lake Bleu Capital, which are based in Hong Kong and between them manage more than $20 billion, have made dozens of investments in private companies since the beginning of last year, according to public filings and people familiar with the matter, who asked not to be identified discussing private information.

The influx of hedge fund money is increasing competition for stakes in the most promising companies before they go public, a space where global firms like Tiger Global Management and Japan’s SoftBank Group Corp. are prolific investors. The region’s hedge funds are looking beyond listed companies as it becomes harder to generate the returns that investors are seeing in private markets.

“We are seeing a proliferation of hedge funds,” said Eric Woo, co-founder of Revere, a San Francisco-based asset manager focused on venture capital. “They can be quite disruptive, because they can be a lot more fast-paced and bring competition to traditional venture funds.”

Asia has more than a quarter of the world’s 700 or so private companies valued at more than $1 billion known as unicorns, according to CB Insights. In addition to venture firms, private equity are also investors in such companies.

Aspex Management, which managed $5 billion at the end of March, has participated in private financing rounds of at least five companies. Tybourne, with $8.6 billion under management, made investments in a Vietnamese e-wallet company and pharmaceuticals. Healthcare specialist Lake Bleu manages almost $3 billion and has made more than 40 private investments since 2018, a person with knowledge of the matter said.