Over the past few weeks the market has been treated to some fireworks thanks to Reddit’s r/wallstreetbets forum.

A few stocks have “mooned,” the internet term for a big surge. Among them: Video game retailer GameStop (GME) is up 750% year-to-date, BlackBerry (BB) 179%, mall retailer Express (EXPR) 346%, real estate investment trust Mac (MAC) 98%, and Nokia (NOK) 25%.

These stocks have been discussed and promoted on the popular Reddit message board, which started stirring up the investing world late last year with irreverent meme-based style. Throughout the pandemic, the rise of a new generation of daytraders, often trading for free on Robinhood, would exert enough force as a group to make wild things happen to stocks, like spike shares of bankrupt car-rental company Hertz (HTZ).

Here are this month’s gains:

In some cases, the stocks that have popped have done so because of a short squeeze.

“This is not really a new thing, just a turbocharged version of the classic short squeeze,” said hedge fund veteran and DataTrek Research co-founder Nicholas Colas. “We saw it with [Carl] Icahn and [Bill] Ackman on Herbalife, and it’s a game hedge funds have played amongst themselves for decades.”

Now, “retail has the power of the internet to crowdsource a squeeze, and they're clearly learning how to do it now as well,” Colas said.

Hedge funds, such as Melvin Capital and Citron Research, have been betting GameStop shares would go down, and these retail investors have popularized the stock enough so that the price is rising, putting a “squeeze” on those who sold the stock short. If a short seller is squeezed, they might have to go out and buy the stock — at a loss — to cover their potential losses, which can be astronomical.

January’s crop of stocks with big pops also include NIO (NIO), AMC Entertainment (AMC), and Robinhood favorite Plug Power (PLUG). One of the things these retail investors seem to love is anything with the potential for big gains — often high-volatility stocks or cryptocurrency. (The current speculative environment is best summed up by my colleague’s tweet Tuesday at 4 p.m.: “CASINO CLOSED.”)

[Read more: GameStop phenomena is about 'the poor vs rich': Reddit WSB user]

Also on Jan. 26, the investor behind the GameStop trade on r/wallstreetbets posted a screenshot of his portfolio that went viral — it showed he had turned his position from around $50,000 to more than $22 million. These sorts of successes and articles (like this one, even) will likely convince others to try their hand at speculative short-term mega gains.