[Ark Invest Increases $20.5 Million in SpaceX Stock, Reduces $4.1 Million in Robinhood] BlockBeats News, on July 21, Cathie Wood's Ark Invest purchased 170,634 shares of SpaceX on Monday, equivalent to approximately $20.5 million. At the same time, it sold 41,322 shares of Robinhood, equivalent to approximately $4.1 million.