I'm not a stock market guy, but this Gamestop / Reddit drama is interesting.

Background:

GameStop is a stock that is usually subject to shorting. That's when an investor borrows shares, sells them, buys them back at a lower price and profits. Ex: One share of X is borrowed, sold at $10/share, bought back at $8/share and returns the stock to the lender. The short results in a $2 gross profit.

Because the investor has to buy back the shares in order to return them to the lender, the volume of buying back can result in a short squeeze - where the value of the stock rises. Sometimes it rises to more than the sell price, resulting in a loss to the speculator.
Ex: One share of Y is borrowed, sold at $8/share, a short squeeze causes the price to rise to $10/share and the investor loses $2 to buy back the stock he has to return to the lender.

The reason people short stocks is that it's a way to profit when the market isn't gaining (stock values aren't rising).

Reddit Drama:

Andrew Left of Citron posted on Twitter that GameStop was a good short. A Reddit subforum r/wallstreetbets organized to beat the short-sellers. A bunch of malcontent millennials, $600 stimulus checks in hand (as the narrative goes), bought enormous amounts of GameStop shares. The stock price has gone from ~$20/share to currently ~$390/share. Professional investors specializing in short-selling are on the hook to lose billions, as they must buy back the shares they have borrowed and sold. The Reddit subforum was temporarily closed, trading on GameStop stock has been frozen, and some retail investment sites do not allow transactions on GameStop.

Thoughts:

I'm still processing what I think about all this. On a superficial level, the Schadenfreude of the investor class losing billions is delicious. Similarly, an army of retail investors organizing on Reddit to out-maneuver the professionals is brilliant and impressive. Someone used the phrase "Storming the Capital".

The other side is that these short-selling hedge fund managers are losing their investors' money. Those investors aren't just wall-street types. They're average Americans' retirement investments - so Redditors are screwing over moms and pops (or grandma and grandpa). There is even mumbling of some of these investment funds needing "bailed out" due to the losses.

The last piece I'm contemplating is how the market has reacted. If you or I were poised to lose a lot of money, the investor class certainly isn't going to freeze trading to prevent it (especially if they're going to profit from it). We know the professional (and political) classes benefit regularly from sharing information and capitalizing on it. The shoe is on the other foot now. With this demonstrated ability of the internet to organize investors to manipulate the system, is that too much volatility? I suppose that if you don't gamble on projected losses (short-selling), then it's not that big of deal.

There are plenty of articles, and This CNN piece isn't bad for it's comprehensiveness.