Following the failures of US banks Silicon Valley Bank and Signature Bank, shares in the US financial and brokerage firm Charles Schwab fell Monday, as fears reverberated through the financial sector of a further spread of the crisis.

In the Texas-based company’s worst single-day sell-off since April of 2000, the stock slid by over 20% during Monday’s session.

The sell-off came amid the company claiming it was a sign of its resilience that it endured a 28% year over year fall in average margin balances in February.

Chief Financial Officer Peter Crawford reassured shareholders and clients in a written statement, telling them that cash outflows were not accelerating month over month, and 80% of the brokerage’s deposits are insured by the FDIC.

He wrote, “These outflows reflect a continuation of client decisions to reallocate a portion of their cash into higher-yielding cash alternatives within Schwab. Based on our ongoing analysis of these trends, we still believe client cash realignment decisions will largely abate during 2023.”

Ranked number eight by assets among US banks, Schwab holds $7.05 trillion in client funds and had 33.8 million active brokerage accounts, as of the end of last year. Many analysts believe the bank is not in any danger due to the robust liquidity it enjoys.

Morningstar analyst Michael Wong wrote in a note, “Many banks and companies with related banking entities, such as Charles Schwab, also have a material amount of fixed income securities on their balance sheet with unrealized losses, as recently rising interest rates have decreased the value of fixed income securities.”

The main motivator behind the selloff in Schwab’s stock was the failures of three major US banks last week. Silvergate, a California-based bank which focused on the cryptocurrency sector was the first to fail, announcing its liquidation on Wednesday of last week. On Friday, Silicon Valley Bank failed, and was taken over by regulators. That prompted users of Signature bank to immediately withdraw $10 billion in deposits.

On Sunday regulators moved in and seized the bank, although executives such as former Senator Barney Frank claimed the bank had no liquidity issues, and the seizure was a pretext to shut down cryptocurrency-focused banking.

These bank failures have sparked broader concerns over the health of the sector in general, and caused many banks to see their stocks plunge.