"There is nothing new in Wall Street," the famed 1920s investor Jesse Livermore wrote. "There can’t be because speculation is as old as the hills. Whatever happens in the stock market today has happened before and will happen again."

The original "Wolf of Wall Street," Livermore's most famous bet was shorting stocks ahead of the crash of 1929. He made a fortune, as did more modern stock shorters like Jim Chanos, who tabbed Enron as a fraud, and Bill Ackman, who saw Lehman Brothers for the house of cards it was. But shorting stocks isn't for the faint of heart. Most of the time, most stocks along with the broader market go up.

So it takes a certain kind of investor personality to bet against a hot stock and stick with it. Lately, there have been some questionable high flyers, particularly in tech, and my Fortune colleague Bernard Warner spent some time talking with a couple of the investors who decided to go short (and go public) against the grain. His profile of the shorters includes Muddy Waters chief investment officer Carson Block, who took down Luckin Coffee, and Fraser Perring, founder of Viceroy Research, who scored on Wirecard. And don't forget Hindenburg Research founder Nathan Anderson. He's the guy who figured out that Nikola had rolled that truck downhill.

“I think fraud is more pervasive than at any time I’ve been in the market, certainly,” Anderson told Bernard. Despite the accurate takedown of Nikola, however, short sellers still aren't popular on Wall Street. “We get more angry emails, or death threats to murder me and my entire family.”

And not every short seller target collapses in a heap of fraud and scandals. Among the largest short positions today you'll find many of the year's hot tech stocks, including Snap, Beyond Meat, and Peloton.

The inflating bubble in electric vehicle stocks has also drawn attention and the biggest target of short sellers over the past few years has been Elon Musk's electric car maker, Tesla. It hasn't worked yet. Short sellers, including Enron-conquerer Jim Chanos, have lost so much money betting that Tesla's stock price would collapse (it's up almost eightfold this year) that Institutional Investor dubbed it the "widow-maker trade of 2020." By this month, the cumulative loss of shorters on Tesla exceeded $35 billion. Yikes.

Chanos hasn't given up though he's said to have scaled back the size of his bet. “However you might want to dream about autonomous taxis, spaceflight, tunnels underground, whatever—they are a car company, and they are an unprofitable car company," he told a Barron's conference this week. Time will tell whether Tesla's stock price can stay aloft or whether, somehow, this time is different.