Shares of Bitcoin mining companies rallied sharply on Friday after trading firm Jane Street disclosed sizable positions in several key miners.

According to filings with the U.S. Securities and Exchange Commission, Jane Street’s trading affiliates hold roughly 5.4% of Bitfarms, 5% of Cipher Mining, and 5% of Hut 8. The stakes represent passive trading positions rather than activist investments.

Following the news, the stocks saw strong gains on Thursday, which continued into Friday. At market close, Bitfarms rose 10.68%, Cipher Mining surged 19.73%, and Hut 8 climbed 17.27%, according to Yahoo Finance. Other miners, including American Bitcoin Corp. (+11.29%), IREN Limited (+12.60%), and Hive Digital Technologies (+17.77%), also posted notable gains.

This disclosure follows Google’s 5.4% stake acquisition in Cipher Mining on September 25, highlighting growing institutional interest in Bitcoin mining operations. Jane Street first signaled exposure to the sector in 2023 through its Marathon Digital (MARA) holdings.

Bitcoin mining—solving complex computational problems to validate transactions and release new Bitcoin—remains crucial for the network’s security. Over the past year, many publicly traded mining companies have outperformed Bitcoin itself. Bitfarms is up nearly 131%, and Hut 8 has surged around 211%, compared with Bitcoin’s 73% gain over the same period.

The strong institutional inflows suggest continued investor confidence in Bitcoin mining firms as a growing segment of the cryptocurrency ecosystem.