NEW YORK (AP) – It’s turning out to be one costly glitch.

A technical problem that briefly threw dozens of stocks into chaos Wednesday will cost Knight Capital Group $440 million, the trading firm said Thursday. Knight’s own stock plunged for a second day, erasing 75 percent of its value in two days. The company also said it is pursuing ways to raise money to fund the expense, raising questions about the firm’s viability. And at least two financial institutions announced they had halted trading with Knight, at least temporarily.

Knight’s embattled CEO Thomas Joyce appeared publicly for the first time Thursday to defend his firm in the aftermath of the trading disaster.