By Hannah Lang (Reuters) – Robinhood Markets Inc became a household name ahead of its stellar IPO last year, when retail investors used its trading app to drive shares of GameStop and other “meme stocks” into the stratosphere, but name recognition has not helped its share price lately. “The market is not being very patient with them,” said Greg Martin, co-founder and managing director at Rainmaker Securities, a brokerage specializing in private company deals. Waning investor interest in retail trading has weighed on shares of the commission-free online brokerage, which saw explosive growth at …