Archegos Ripples Through Banks’ Lucrative Hedge Fund Business

The collapse of Archegos Capital Management LP, an investment firm that few even on Wall Street had heard of until it imploded last month, is changing a lucrative, decades-old part of global banking.

Nomura Holdings Inc. and Credit Suisse Group AG, the two lenders hit hardest, have started to curb financing in the business with hedge funds and family offices. European regulators are looking at risks banks are taking when lending to such clients, while in the U.S., authorities started a preliminary probe into the debacle.

Together, steps taken from Washington to Zurich and Tokyo could portend some…