Rewind to September: Shares of Facebook touched an all-time low of $17.73, while Apple's stock closed near an all-time high of $674.97.
Since then, Facebook has rocketed nearly 70 percent compared to a 22-percent decline for Apple.
That meteoric rise has made Facebook one of the best-performing stocks in the Nasdaq 100. Apple, on the other hand, is the worst.
During Wednesday's trading session, Facebook closed above $30 a share for the first time in 6 months.
A rolling 60-day correlation between AAPL and FB is at its lowest level on record. In fact, the two stocks have a negative correlation, implying that as one stock rises the other one falls, and vice versa.
While not a fool-proof strategy, if the negative correlation persists, FB may actually work as a hedge for AAPL.