What happened

Less than a week after UP Fintech Holding (NASDAQ:TIGR) stock sold off in response to Q1 earnings, shares of the Chinese online brokerage are rebounding nicely today -- up 10.5% as of 1:15 p.m. EDT -- on news that the company has a big fan in the United States.

That would be Greenwich, Connecticut-based Interactive Brokers (NASDAQ:IBKR).

100-yuan bills fanned out atop a business newspaper

Image source: Getty Images.

So what

In a Schedule 13D filing last night with the Securities and Exchange Commission, a company related to Interactive Brokers -- IB Global Investments LLC (IBGI) -- disclosed that with UP Fintech's recent initial public offering, IBGI converted its 137,635,322 Series B-3 preferred shares, purchased last year, into an equivalent number of Class A ordinary shares of UP Fintech. In addition, IBGI purchased 13,125,000 more shares of common stock in UP Fintech "in a concurrent private placement transaction for $7 million."

As a result, IBGI now owns nearly 150.8 million shares of UP Fintech. That amounts to 7.6% of Class A ordinary shares, according to the filing. 

It's clear that IBGI seems to think that UP Fintech is a worthy investment. It appears that, based on that assessment, other investors are buying in today.