There’s the worry that the exuberant small-time investors who flocked to the online brokerage won’t stick around for the long haul. Or that trading in Dogecoin, which started as a joke, accounted for more than a third of its cryptocurrency revenue in the first quarter. Or that just this week, a Wall Street watchdog levied a record $70 million penalty against the firm.
Yet the company that introduced an army of young traders to the ins-and-outs of investing is still seizing its moment, filing for an initial public offering Thursday ...