U.S. investor Sung Kook "Bill" Hwang was looking for a second chance on Wall Street after falling from grace and shutting his multibillion-dollar hedge fund firm. Japan's Nomura Holdings Inc. gave him one.

Nomura had previously had a relationship with Hwang's Tiger Asia Management LLC before the investment firm shut down in 2012 after being punished by U.S. and Hong Kong regulators over insider trading of Chinese stocks.

Like other banks, it initially did not resume the business relationship with the Korean American investor's new family office, Archegos Capital Management, according to one person familiar with the situation. But Hwang's appetite for huge bets on technology, media and other company stocks in the United States and Asia proved too lucrative to resist.