$900 under, did you buy at $650 or higher? I say if you're that far under, it's a hold in the stock unless you can take the loss. See how things go after the market opens again on Wednesday. Keep in mind that AAPL dropped 50 points the day Steve Jobs stepped down as CEO (from ~400 down to 350) and recovered in a few days.
Much of the recent selling has been due to forces outside of Apple (economic globalization, world economic worries, and growth concerns) and not due to the health of Apple as a company. AAPL's recent "miss" in Q4 2012 is linked to known product cycles and rumors that caused customers not to purchase products this quarter and analysts' overblown estimates.
Personally, I think AAPL will begin to recover as we get closer to the dividend and continue to recover into the holidays and be above $650 by the end of the year. When they announce holiday earnings in January they'll be back at $700 and continue to climb into Q2 2013.
Full disclosure, I do trade and am currently holding a long position in AAPL. I last bought at $590. According to the technical chart that I use to track AAPL, the stock is severely oversold and due for a rally.