Silvergate Capital fell Tuesday, even after the company's CEO released a public letter attempting to "set the record straight" about its role and current state in the crypto ecosystem.

Shares were last lower by 4.7% after falling as much as 13% in premarket trading. Speculation has been swirling around the crypto friendly bank in the wake of the FTX blowup, as investors try to decipher Silvergate's relationship with FTX and potential impact from it. Silvergate has said that relationship is limited to deposits.

Pressure mounted on the stock after NBC News reported early Tuesday Sen. Elizabeth Warren, D-Mass., along with two Republican colleagues sent a letter to Silvergate CEO Alan Lane requesting information about the crypto friendly bank's relationship to FTX and other entities headed by Sam Bankman-Fried.

Silvergate shares dropped 8.5% on Monday.

"It has been a very difficult few weeks for the digital asset industry, as we have all come to terms with the apparent misuse of customer assets and other lapses of judgment by FTX and Alameda Research," Lane said in the letter, released Monday night. "There has also been plenty of speculation – and misinformation – being spread by short sellers and other opportunists trying to capitalize on market uncertainty."

Silvergate recently disclosed that FTX deposits at the bank represent less than 10% of its total deposits from crypto customers. It has also said it has no outstanding loans or investments in the crypto exchange.

Since the sudden collapse of FTX in November, Lane has reiterated in interviews, including on CNBC, that the bank has a resilient balance sheet and ample liquidity should it need to satisfy withdrawal requests. He also repeated this in Monday's letter.

"While this has been a turbulent time in the digital asset industry, our customers' deposits are, and have always been, safely held," Lane said. "We intentionally carry cash and securities in excess of our digital asset related deposit liabilities."

He also wrote that the bank has conducted "extensive due diligence" on FTX and its sister company, the trading firm Alameda Research, and that it takes risk management and compliance "extremely seriously."

Research from KBW backs up the idea that Silvergate's relationship with FTX platforms was "extremely limited" based on the company's own bankruptcy filings, according to analyst Michael Perito. He said in a note Tuesday that most customers were "likely transferring value onto the FTX exchange via crypto and digital wallets versus fiat transfers from banks."

"Weeks have now passed since the FTX bankruptcy and initial misleading social media claims that SI was involved began," said in the note. "SI is a highly regulated institution (Federal Reserve is its primary regulator), with Crowe LLP serving as its auditor. If the bank's regulators were highly concerned about activity ongoing at SI, it would be a fairly quick process to identify those problems, in our estimation, and shouldn't take multiple weeks."

Wedbush noted that while Silvergate facilitating payments to Alameda was "consistent with normal business practices, the letter also didn't provide a current deposit update. That implies the company "may continue to experience deposit pressure," Wedbush analyst David Chiaverini said in a note Tuesday.

—CNBC's Michael Bloom contributed reporting