SoftBank is the “Nasdaq whale” that has bought billions of dollars’ worth of US equity derivatives in a move that stoked the fevered rally in big tech stocks before a sharp pullback on Thursday, Financial Times reported on Friday, citing sources.

According to people in the know, the Japanese conglomerate has been snapping up options in tech stocks over the past month in huge amounts, contributing to the largest trading volumes in contracts linked to individual companies in nearly 10 years.

One banker, Financial Times said, described it as a “dangerous” bet. The aggressive move into the options market marks a new chapter. The investment powerhouse has made huge bets on tech start-ups through its $100-bn Vision Fund. After the Covid-19 market tumult hit those bets hard, the firm established an asset management unit for public investments using capital contributed by its founder Masayoshi Son.