Today's market was largely influenced by December same-store sales results released by America's top retailers. While the holiday shopping season started off slowly, it appears that business overall wasn't as bad as some thought earlier on. Thursday's stock market action showed a clear divide between those that did well, and those that did not. Most retailers reported sales growth above consensus, but the stocks reacted violently in both directions.

As is always the case, Wall Street's obsession with short-term results presented investors with many opportunities today, as retailers were among the day's most active stocks. Ann Taylor (ANN) shares rallied after getting decimated late last year. Urban Outfitters (URBN) got hit after warning that 15 percent comp store sales gains could not be sustained (did anyone really think they could be?). Aeropostale (ARO) was one of the only teen retailers that did not do well, and a pair of analysts downgraded the shares based on a single lackluster month.

Most investors will sit tight, but they should really be stepping up to the plate. ARO trades at 13.5 times 2005 earnings with growth expected to be 20 percent. Makes no sense. URBN stock is reacting to less-than-expected momentum at existing stores, but their nationwide expansion plans are the reason to own the stock. I added to my position in the latter and initiated one in the former. Volatility like we saw today should make opportunistic investors salivate.