Customers of the US bank Silvergate, one of the few mainstream financial organisations that focuses on providing services to the cryptocurrency sector, have pulled more than $8bn (£6.7bn) of their crypto-related deposits from the lender.

More than two-thirds of customers’ deposits were withdrawn in the final three months of 2022, as the collapse of the FTX exchange reverberated around the cryptocurrency world.

While most of the impact from the collapse has so far been felt only by other organisations and individuals in cryptocurrency, limiting the “contagion” to the wider economy, Silvergate, an otherwise conventional bank, has been forced to take extraordinary action to protect its balance sheet.

The bank said on Thursday it was forced to sell $5.2bn worth of assets for cash “in order to accommodate sustained lower deposit levels and to maintain a highly liquid balance sheet”, and booked a loss of $718m on those sales.

“In response to the rapid changes in the digital asset industry during the fourth quarter, we took commensurate steps to ensure that we were maintaining cash liquidity in order to satisfy potential deposit outflows, and we currently maintain a cash position in excess of our digital asset related deposits,” said Alan Lane, the chief executive of Silvergate.

The bank attributed the withdrawals to a “crisis of confidence across the ecosystem” that had led many to seek to reduce their risk to digital assets.

Based in California, the bank’s…