July 30 (Reuters) - Stockpicker Cathie Woods’ ARK Invest bought about 1.3 million shares of Robinhood Markets Inc , according to the firm’s daily trade summary on Thursday, when Robinhood debuted on the stockmarket with a grim first day’s trading. Robinhood’s shares closed more than 8% lower at $34.82 per share on their first day, as many investors who used the popular trading app to participate in this year’s “meme” stock trading frenzy snubbed its initial public offering (IPO). According to ARK’s daily update for its actively managed ETFs on Thursday, it bought 1,297,615 shares of Robinhood in its ARK Innovation ETF. At the closing price, that would have been worth around $45.2 million. Some IPO investors stayed on the sidelines, citing concerns over its valuation, the risk of regulation, and lingering anger with the company’s imposition of trading curbs during the meme stock trading frenzy in January. In an unusual move, Robinhood had said it would reserve between 20% and 35% of its shares for its users. IPOs can benefit from excluding retail investors, who end up fueling a first-day trading pop by snapping up shares in the open market. Data from Fidelity Investments here showed customers on its brokerage platform placed 31,736 buy orders for Robinhood"s stock and 7,451 sell orders on Thursday. On Friday, Robinhood was trading 0.2% lower at $34.75 before the bell. (Reporting by Megan Davies and Aaron Saldanha in Bengaluru, Editing by Louise Heavens) Our Standards: The Thomson Reuters Trust Principles.