You think the stock market is filled with "rational" actors? It has always ALWAYS been a vibe check since its existence. The Tesla stock is obviously overvalued, not because there is some grand conspiracy to prop up the stock by a bunch of retail investors but because Elon is a hype man and he hypes up his own stocks. Tesla being overvalued is not a new phenomenon
Mania's have been a thing since the start of markets.
It's so funny to see HN readers who know absolutely nothing about finance or capital markets have "houlier-than-thou" attitudes towards institutional money.
> why would I do something rational in a broken market
Why do you think you're the rational one?
That's the entire point of how markets work. No one thinks markets are fully efficient and the way you make money by trading is through exploiting inefficiencies.
The market was in a panic mode around Facebook a year and a half ago and if you were smart enough to see that and take advantage then you'd have 4x'd your investment.
But I guess you're "too rational" to make money off that sort of thing?
As popularized in "The Big Short": https://en.wikipedia.org/wiki/Michael_Burry
> During his payments toward the credit default swaps, Burry suffered an investor revolt, where some investors in his fund worried his predictions were inaccurate and demanded to withdraw their capital. Eventually, Burry's analysis proved correct: He made a personal profit of $100 million and a profit for his remaining investors of more than $700 million. Scion Capital ultimately recorded returns of 489.34% (net of fees and expenses) between its November 1, 2000, inception and June 2008. The S&P 500, widely regarded as the benchmark for the US market, returned just under 3%, including dividends over the same period.
Why?
The more people shorting something, the better chance for short to succeed. It's in the best self-interest of all people shorting something to be as loud as possible about that.