There is no way for me to ignore soft ground, or find a decent news stories on this. As we all know by now, Facebook set the price at $38, it opened at $42, fell multiple times to around $38.00, then closed up $0.23 (twenty-three cents) (0.6 percent higher) on the first day of trading. During trading it was reported that the Underwriter (Morgan Stanley) had to repeatedly defend the opening price by buying any stocks offered that would lower the price below the IPO price. The number of share MS had to buy can cannot be found, but I have heard rumors that they purchased 11m of 16m shares. Again, the answer cannot be found. However, the WSJ blog reports some of the details on this standard practice.
The WSJ Blog also reports the total share traded for the day 421.2 million - reportedly a record number of trades on an opening day for this type of stock.
At 10am Pacific time the stock price continues to fall below the IPO price. Currently trading around $34.15, down $4.18. It is worth noting that the day before the IPO FB was trading around $36 per share in private markets.
UPDATE (2:05pm Pacific Time): FB closes down $4.20 at $34.03 for the day (4pm EDT).
FB is traded on the NASDAQ