I think those who held onto it when they bought the initial stock are happy with their gains. If the current price is stable or even growing, that means it was never over-valued. You are thinking too short term.
If you have bought a stock at one price, and it currently has a higher price, that means you have made a good investment, regardless of what happened in between.
This is a matter of your investing preference and whether you are a buy-hold investor or a day-trader type who wants to get in at the lowest price. I simply wanted to point out I was skeptical and that FB stock tanked after IPO. I am by no means an expert on the stock market or IPOs :)
If you have bought a stock at one price, and it currently has a higher price, that means you have made a good investment, regardless of what happened in between.