Oil: What goes up...

NEW YORK (CNNMoney.com) -- Oil's on sale!

Okay, not really. At about $124 a barrel, crude is still up substantially from a year ago. But it's down 15% in just a couple of weeks, and the threat of $150 oil has faded for now.

The stock market has taken notice. Despite some not-so-great news from many banks, stocks overall have rallied.

So why is oil falling? And can it continue to do so?