Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of ReachLocal (Nasdaq: RLOC) jumped as much as 15% today on unusually high volume.

So what: With nearly three hours left in the trading day, 240,000 shares have traded hands, nearly six times the normal volume. The short interest has been building consistently since ReachLocal's IPO in May, and we could be seeing the short squeeze starting.

Now what: Shares have settled lower after the initial spike, but without substantial news I don't see this move as a reason to get in today. This Motley Fool Rule Breakers pick still has lots of growth potential going forward as buying on a day like today can leave long-term investors exposed to the whims of traders starting the new year. I will wait for a better entry point after the New Year's jump fades.

Interested in more info on ReachLocal? Add it to your watchlist.