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 surf-inspired apparel-maker Quiksilver (NYSE:ZQK) were riding the perfect wave today, jumping as much 11% today on an upgrade from Stifel Nicolaus.

So what: The investment house raised its rating from "Hold" to "Buy," giving Quiksilver a $6 price target on "hints of stabilization" in Europe that it believes could boost revenue and margins in the coming fiscal year. In September, Quiksilver shares jumped 17% on its last quarterly report, though it has given back some of those gains since then, an indication of uncertainty about the stock.

Now what: A single upgrade usually isn't enough to send shares climbing like this, but Quiksilver, which is also the parent of Roxy and DC brands, has been looking for some good news for a while. This is still primarily a turnaround story, as shares are well off of pre-recession highs. The company's debt load is worth more than its market cap, and revenue crept only 2% higher in its last quarter. Shareholders can take some comfort in knowing Stifel Nicolaus sees things their way, but I'd rather be convinced by hard numbers.

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Jeremy Bowman and The Motley Fool have no positions in the stocks mentioned above. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.