Facebook's share price closed down $3.03 or 8.9% at $31 in New York today.
In its three days of trading, Facebook's stock has dropped 18.4% from its $38 issue price.
For the thousands of investors that bought at the IPO, that's bad enough, but one analysis of its earnings prospects suggests it could get a lot worse - more like $10 a share.
Setting aside the hype and the cultural phenomenon that is the online networking site, Facebook Inc would be fairly priced at $9.59, according to the smattering of Wall Street estimates analyzed and modeled by Thomson Reuters StarMine.
Facebook and Morgan Stanley are being sued by shareholders who claim weakened growth forecasts were hidden ahead of shares being sold.
If Facebook can get around privacy issues to use advertising better and capitalise on markets like China and Russia, prices should recover.
After all the hype about the most expensive flotation of a company ever, Facebook shares are well down on what they were when launched.