(Bloomberg) -- Cathie Wood’s recent travails have been a boon for some of her peers in money management.About two dozen investment advisers including Balyasny Asset Management and a unit of Blackstone Group Inc. bought bearish put options during the first quarter on the Ark Innovation exchange traded fund, her firm’s main investment vehicle, regulatory filings show.

While money managers often buy puts on ETFs to protect their portfolios against market declines, the options are typically tied to passively managed index funds such as the SPDR S&P 500 ETF Trust.

Yet technology-focused Ark Innovation grew so large so quickly -- to $28 billion in mid-February from $1.9 billion at the end of 2019 -- that some managers saw the actively managed fund as a better alternative to buffer against a slump in stocks that surged during the pandemic.

Big Take: Cathie Wood’s Bad Spring Is a Blip When Future Is So Magnificent

“The Ark Innovation fund had a tremendous run over the course of 2020 and early 2021,” Efrem Kamen, the head of New York-based Pura Vida Investments, said in an email. “However, the level of fund flows into the ETF appeared to be extreme.”