Brendan Blumer, CEO of Block.one, which developed the EOSIO blockchain platform and EOS (EOS) coin, has purchased a stake in Silvergate Capital, the holding company for Silvergate Bank, a crypto-fiat gateway network designed for financial institutions, according to an SEC filing. That document, dated Nov. 23, listed Nov. 16 as the date of the transaction.

The purchase of nearly 3 million shares represents 9.27% of Silvergate stock. Blumer purchased 571,351 shares personally, and Block.one purchased 2,363,186. According to CNN, this deal will make them Silvergate’s largest shareholder.