In an opinion piece for Bloomberg, Kevin Muir writes that bubbles always seem obvious and easy to trade—in hindsight. But in the current view, they definitely are not. What made opportunities like the real estate collapse of the mid-2000s and the Dotcom bust before that so successful was that so few people believed they could happen.

Bubbles, Muir contends, are extremely difficult to spot, and even harder to trade. He points to his own experience in 2005 when he shorted a basket of homebuilder stocks, believing the sector was vastly overpriced. The trade flourished for 2 months but when homebuilder shares tore higher by 35%, he was tossed out of his short positions.

The honest and ugly truth about bubbles, Muir writes, is that pretty much everyone winds up losing out. Bears leave the party too soon, with the majority given up by the time the market shifts, and bulls, who are trained to buy at every dip, remain at the party way past their welcome. And while bubbles used to be rare, the markets have evolved into a series of “rolling mini-bubbles,” with the boom of hedge funds decreasing available alpha and price action encouraging “momentum-chasers.”

When the market bottomed out in March 2020, the Goldman Sachs Non-Profitable Technology Index had fallen 40%. That attracted short sellers, and then the shares rallied 38% over summer 2020 and went on to skyrocket an incredible 478%. With many financial leaders touting the virtues of tech and innovation, skeptics began to fear shorting as a result of these volatile rallies. Now, that index has dropped 41% from its 2021 high, leading to some very bruised and battered bulls and bears alike.

Hindsight may tell us, years from now, these stocks were overvalued but in the midst of this wild ride, it’s anything but obvious.