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

Retail stocks can be a lot like the merchandise and the sales of the companies they represent -- in constant fluctuation. In this column I like to point out a few notable daily moves from the big retail stocks and help investors figure out whether they should buy, sell, or hold. Today's movers and shakers: lululemon athletica (LULU 1.43%), Under Armour (UAA 1.81%), and Crocs (CROX -0.45%).

This stock wasn't a lemon today
Shares of Lululemon rose 0.72% today and another 0.45% in the after-hours session following an analyst upgrade today. Oppenheimer raised its rating from "perform" to "outperform" and increased its 12- to 18-month price target to $63. Based on today's after-hours session closing price of $51.65, that would represent a nearly 22% increase. That would be a healthy price appreciation, but even though I'm a shareholder, I'd keep this stock at a hold. The growth Lululemon would need to justify that valuation is going to be difficult to pull off. The new management team has a long road ahead, and I'm going to hold my shares for now, with plans to re-evaluate my position in a few quarters.  

Investors don't need protective armor here
I also own shares of Under Armour, whose new uniforms were taking the blame for the U.S. speed-skating team's poor performance in the Olympics. Over the weekend, the skaters in Sochi switched back to an older Under Armour uniform, but the poor performance continued. Investors seem split over whether the controversy is good for the company, but I think the stock and the company will both be fine when the dust settles. After trading as low as $103.00, the stock closed today at $107.46, an increase of $1.46, or 1.38%. I rate the stock a buy, and maybe other investors are coming around to the same opinion.

A dangerous animal to mess with
Finally, shares of Crocs dropped 3% today. The move comes on very little news, though the company is expected to report earnings tomorrow. Analysts are expecting revenue to come in at $221.24 million, which would be a 1.7% sales drop from last year, and for earnings per share to hit negative-$0.22, down from a positive-$0.04 reading. The only good news is that if results meet the dreary estimates, it could limit some of the downward pressure on the stock. But I never like to trade within a few days of an earnings release, because of the added volatility, so for now I'd rate this stock as a hold.