The share price is only down a small amount, which can be attributed to normal market noise. This is actually an indicator that the iPhone is performing (over 500,000 sold) just about where financial analysts expected it to. If it had outperformed expectations you'd see huge abnormal gains, and if it had underperformed you'd see enormous capital losses. These two scenarios can still occur as more information comes out about the iPhone's sales, but for the moment it appears that analysts predicted sales fairly accurately and began pricing their estimates into Apple stock from when the product was first announced.

Personally, I short sold (bet against) a large amount of Apple stock last Friday. I feel like the iPhone has been over-hyped and the Apple loyalists are influencing the share price more than they should be in a relatively efficient market.

For those who are more risk averse than I am, it's potentially a bad security to be holding at the moment. Large fluctuations in share price are certainly possible in the coming weeks if analysts turn out to be wrong in either direction.