Cathie Wood is known for making bets on technology stocks that have the potential to significantly disrupt industries.In mid-December, Cathie Wood of ARK Invest snapped up shares of the popular retail brokerage Robinhood (HOOD 1.78%) to the tune of 13.4 million. That's not an insignificant buy, considering ARK's Blockchain & Fintech Innovation ETF owns over 59 million of Robinhood stock. Robinhood is now the fund's fourth-largest holding, accounting for roughly 5.2% of its investments.Robinhood has had a ...