"At this point, like I said, I don't care about what my financial return is, now it's about sticking it to the man."

Collin McLelland's a 31-year-old investor and podcaster from Houston, Texas.

He and thousands of investors like him took on Wall Street and sent shares in U.S. gaming retailer GameStop soaring.

"So I first started seeing some commotion around Reddit on WallStreetBets forum talking about GameStop and essentially, executing a short squeeze on Melvin Capital, which is a hedge fund. And I thought it was really interesting because you saw the common man fighting against Wall Street. So I put some money in the stock, around $85, out of just principle. I thought it was comical."

Online brokerages including Robinhood then temporarily restricted trading in those stocks on Thursday (January 28), much to the anger of the online community, including investment vlogger and Robinhood user JJ Buckner.

They accused the trading platforms of seeking to protect Wall Street's interests at the expense of smaller investors.

"Robinhood is not my mom and dad and they can't tell me when I can and can't trade. You know, they, they like to make the - there was an email sent out saying that we're looking out for our investors. No you're not. The investors, we know what we're doing. We live in a free country. We live in a free, let us live in a, trade in a free market, where we're able to dictate what happens with our money. If I want to risk my money to potentially earn some more because I know what's going on, and I want to take advantage of the opportunity, let me do that. Don't tell me you're looking out for me when we all know that prices were going to go up."

By the end of Thursday's trading session, Robinhood reversed course and said limited trading in the stocks would resume on Friday (January 29).

"That's what it is. It's the regular Joes versus Wall Street. When I put money into it, I said: even if this goes to zero and I lose everything, I like being a part of it. I think that that sentiment is shared among a lot of people."

Regarded by market professionals as "dumb money", retail traders - some of them former bankers working for themselves - have become an increasingly powerful force of the financial world.

That's sparking calls for greater scrutiny into trading on easy access online apps fueled by anonymous discussions on social media.