Cathie Wood’s ARK Autonomous Technology & Robotics exchange-traded fund has bought shares of a blank-check company backed by tennis star Serena Williams.

In recent days the ARKQ ETF purchased about 800,000 shares in Jaws Spitfire Acquisition Corp., according to data from ARK Investment Management LLC. Jaws Spitfire, which counts Williams as a board member and Starwood Capital LLC Chief Executive Officer Barry Sternlicht as its chairman, on Tuesday entered a merger deal with 3D printing company Velo3D Inc. to take it public, sending shares of the special-purpose acquisition company down more than 5 per cent that day.

Wood and SPACs are both having a bit of a rough moment. SPACs tumbled on Thursday in the wake of a report that U.S. regulators will be scrutinizing the blank-check phenomenon, which has exploded in recent months and attracted celebrities like Shaquille O’Neal, Alex Rodriguez and Williams. Wood, who manages multiple funds that returned over 100 per cent in 2020, is now sitting on a year-to-date loss in her flagship ARK Innovation ETF. The ARKQ ETF that bought into Jaws Spitfire is up 5.4 per cent.

Read more: Cathie Wood Says She Has No Second Thoughts: Matthew Winkler

Sternlicht said in a CNBC interview Wednesday that the SPAC market is “out of control.”

Williams also made headlines in the financial world recently when her Serena Ventures joined a US$5 million pre-Series A funding round for Bitcoin rewards company Lolli, along with her husband Alexis Ohanian’s venture capital fund Seven Seven Six.