It's amazing to see the overreaction to daily swings in Apple's (AAPL) stock price. After the huge gains that the stock has seen, a 10% pullback is not anything to be too worried about. I'm on record of not being overly bullish on AAPL moving forward as I worry about their gross margins, and I think that competition will pick up. It's certainly not overtly expensive on a P/E basis though so I do understand how people can have a different opinion. Investors would be wise to look at it as an investment as opposed to a day trading tool, which seems to be the mentality in this obsessive and media driven market environment. If AAPL does stumble that could certainly impact the performance of the S&P 500 due to the large weighting on the index. I wouldn't be surprised at all if more people lose money on the stock then make money even if it goes up, because I suspect there is a lot of market timing going on which usually doesn't end up well.