Global banks may lose more than 6 billion from the downfall of Archegos Capital, sources familiar with trades involving the U.S. investment firm said on Monday, and regulators and investors fear the episode could reverberate more widely.

Japans Nomura and Credit Suisse of Switzerland warned of major losses from lending to Archegos for equity derivatives trades, triggering a worldwide selloff in banking stocks.

Morgan Stanley shares fell 2.6 and Goldman Sachs Group dropped 1.7. Nomura shares closed down 16.3, a record oneday drop, while Credit Suisse shares tumbled 14, their biggest fall in a year. Deutsche Bank dropped 5 and UBS was off 3.8.

Losses at Archegos Capital Management, a family office run by former Tiger Asia manager Bill Hwang, sparked a fire sale of stocks including ViacomCBS and Discovery on Friday, a source familiar with the matter said.

This is a challenging time for the family office of Archegos Capital Management, our partners and employees, company spokesperson Karen Kessler said in a statement. All plans are being discussed as Mr. Hwang and the team determine the best path forward.

Archegos was unable to meet banks calls for more collateral to secure equity swap trades they had partly financed. After those positions fell sharply in value, lenders sold big blocks of securities to recoup what they were owed, the sources said.

When you have people making certain bets based on what has outperformed in the past and the tide turns they get burned….