Polychain Capital is a San Francisco-based venture capital firm that manages a cryptocurrency hedge fund of actively managed blockchain digital assets. The firm's founder, Olaf Carlson-Wee, was the first employee at Coinbase and left the company in 2016 to found Polychain Capital. Polychain launched in September 2016 with $5 million from thirty investors. USV led Coinbase's Series A fundraising round, and Andreessen led its Series B. His fund earned investors 2,303% in 2017, after fees, which was one of the highest returns among billion-dollar investment firms in history. Following the success, Carlson-Wee drew comparisons to Wall Street traders, such as John Paulson and George Soros.

Investors in Polychain capital include Sequoia Capital, Founders Fund, Andreessen Horowitz, Initialized Capital, Pantera Capital, and Union Square Ventures. In 2017, Polychain adopted a strategy that required its investors to increase their original positions by hundreds of thousands of dollars, and those who did not have such capital were forced out. According to Carlson-Wee, this action was necessary as Polychain introduced changes to accommodate larger investors, and only a small number of backers were impacted.

By 2022, Carlson-Wee’s net worth had grown to an estimated $600 million among cryptocurrency investors. One of the most profitable of his early investments was a major stake in ether, the token underpinning the Ethereum blockchain whose value subsequently rose to $3,000, and which traded for less than $12 back in 2016 when Polychain made its first major investment. As of 2022, the cryptocurrency market was estimated at close to $2 trillion, and Polychain’s assets were valued at $5 billion, making for a growth of 125,000% since the company's inception. That same year, the firm had raised $750 million for its third venture fund, led by Tiger Global Management and Temasek Holdings.

Polychain’s main fund takes its fees every year on unrealized capital gains, in comparison to firms holding illiquid assets that are paid upon selling investments. Carlson-Wee started with $14,502 in the fund, and in a few years turned this sum into $150 million of fees. Carlson-Wee and Polychain faced a lawsuit filed in March, 2018 by an early investor, professional poker player Harry Greenhouse. In court filings, Greenhouse claimed he asked for his money to be returned at the end of 2017 and received the price he originally paid as repayment, as opposed to its sale value. He alleged that Polychain would not disclose details regarding the valuing of his investment and suspects he was underpaid.