So-called meme rallies are unusual share price gains, driven by social media sites patronized by individual traders. Online brokerage firm Top Financial Group Ltd. spiked 569% to $133.8 per share in afternoon trading Friday, continuing the trajectory seen during premarket trading and giving the company a market capitalization of about $4.5 billion. The stock had nearly tripled to $20 per share in regular hours on Thursday and closed at a total market value of $701 million.

Magic Empire Global Ltd., a provider of financial advisory and underwriting services, jumped 390% to $4.53 per share. It had closed at $0.93, shedding 7.2%, with a market capitalization of $18.8 million during regular market hours on Thursday. Both Top Financial and Magic Empire are currently two of the most watched stocks on Stocktwits, a website that is popular among retail investors. Magic Empire was the third-most traded stock by retail investors as of 11:30 AM ET (1530 GMT), according data tracked by J.P. Morgan Chase.

Top KingWin Ltd., a provider of consulting and advisory services, gained 33%, and U Power Ltd., which is launching automated battery-swapping stations for electric vehicles in China, is up 27%. Both firms listed on the Nasdaq last week after pricing their respective initial public offerings.

Nasdaq in October put the brakes on IPO preparations of at least four small Chinese companies while it was investigating short-lived stock rallies of such firms following their debuts, according to lawyers and bankers who work on such stock launches.

U.S. exchanges and the Financial Industry Regulatory Authority (FINRA) in November warned about a heightened threat of fraud mostly involving the initial public offerings of small companies, driven in part by a social media-driven pump-and-dump scheme called "pig butchering."