Last week the government decided that investors who think that a companies stinks, can't invest on that notion by short selling stocks if that stock belongs to one of the companies that has recently made really really dumb business decisions (finance companies).
I don't pretend to understand the ins and out of why our politicians think that's fair, but changing the rules in the middle of the game, does not strike me as fair.
So investors can short stocks, investing on the notion that a company is overvalued, unless that company makes really, really, dumb business decisions. In that case, our government will step in and protect the companies.
When investors bought stocks like mad during the late 90's that ultimately led to crappy market conditions, as the market corrected, but no one stopped investors from buying. Of course, that would have protected investors, not companies...
Actually the government did not block everyone from shorting stocks, only you and me. If you are a "market maker" whatever that means, you can short financial companies to your heart's content.
If you are a fund manager, keep on shorting.
For an interesting take on how this decision impacts inverse ETFs like SKF UltraShort Financials ProShares that don't actually short stocks, check out this article.