Source: Shutterstock As Nvidia (NASDAQ: NVDA ) stock sank on Thursday, Ark Invest's Cathie Wood took it upon herself to bolster her holdings of the chip maker — at the expense of one electric vehicle (EV) behemoth. Wood sold more than 115,000 shares of Tesla (NASDAQ: TSLA ) on Thursday to buy an additional 226,000 shares of NVDA stock, worth almost $32 million.