Feb 2 (Reuters) - U.S. custodian bank State Street Corp on Thursday reported a 9.32% passive stake in cryptocurrency-focused lender Silvergate Capital Corp as of Dec. 31, according to a regulatory filing.

The disclosure comes as Silvergate seeks to ease investor concerns over its future, after reporting a $1 billion loss for the fourth quarter because FTX's bankruptcy shook confidence in the crypto sector.

Earlier this week, a group of bipartisan U.S. senators sent a letter to Silvergate asking for details on its dealings with FTX and affiliate Alameda.

Passive shareholders do not seek to influence a company's management or its course of business. (Reporting by Niket Nishant in Bengaluru; Editing by Devika Syamnath)