SoftBank Group Corp is winding down its derivatives holdings following an investor backlash, Bloomberg News reported on Wednesday, citing unidentified sources. About 90 percent of the options, which accompanied SoftBank shifting part of its cash reserves into listed tech stocks, will be closed out by the end of December, Bloomberg said.

The investments by SB Northstar, which is headed by Abu Dhabi-based Akshay Naheta, caused consternation in markets, leading to SoftBank being dubbed the ”Nasdaq Whale” in some media reports.

Chief Executive Officer Masayoshi Son last month described the derivatives as a ”rounding error” when compared to the group’s broader portfolio. The fair value of SoftBank’s options and futures positions was USD 2.7 billion at the end of September, compared to USD 16.8 billion in tech stocks such as Amazon.com Inc.

”(The impact of a wind-down) depends on how much you believe SoftBank was the culprit behind all the option volatility and the whale-type moves,” Andrew Brenner, New York-based head of international fixed income at NatAlliance Securities, wrote in a note.

The company’s shares, which have gained 53 percent this year, were flat in Tokyo trading. A SoftBank spokeswoman declined to comment on the report.