Were You Better Off Buying FB or AAPL?

Chris Ratcliffe | Bloomberg | Getty Images

Facebook may have had a rough go out of the gate, while Wall Street darling Apple got all the attention. But in the past four months, that pairing has been flipped on its head.

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.