Nomura Holdings Inc. is beginning to tighten financing for some hedge fund clients following the Archegos Capital Management LP fiasco that may cost Japan’s biggest brokerage an estimated $2 billion, according to people familiar with the matter.

The restrictions include curbing leverage for some clients previously granted exceptions to margin financing limits, one of the people said, declining to be identified as the details are private. A representative for the Tokyo-based firm declined to comment.

Nomura is taking steps to reduce risk at its prime brokerage unit in the wake of the Archegos collapse that may result in combined losses of $10 billion for global banks, according to estimates from JPMorgan Chase & Co.