Ms. Wood’s ETFs are at the center of the selloff that has pushed the S&P 500 down 7% and the Nasdaq Composite off 12% just four weeks into 2022. Worst hit have been the shares of technology and biotech firms that generate little to no profit, yet carry high valuations—the kind of companies Ms. Wood’s ARK favors.

Some of the holdings of the ARK Innovation ETF are down more than 50% from their recent highs, including Spotify Technology SA, Block Inc., Zoom Video Communications Inc. and Roku Inc.

Ms. Wood insists the fund’s holdings are due to rebound. “After correcting for nearly 11 months, innovation stocks seem to have entered deep value territory, their valuations a fraction of peak levels,” she wrote in a blog post last month.