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 drilling technologist Tesco Corp. (Nasdaq: TESO) look like black gold themselves today, shooting up as much as 10% to set 52-week highs on heavy trading volume.

So what: Tesco got some love from Standard & Poor's analysts today: The stock was already rated a "strong buy" by that firm, but received a "stock of the week" gold star and a video review to boot. For a lightly traded small-cap like Tesco, that's often all it takes to send the stock on a rocket ride -- or a plunge.

Now what: Partly thanks to today's boost, Tesco is on an absolute tear. The stock has gained 84% over the past year and 41% in the past month. S&P lauded the company for solid cash flows, strong innovation, and a debt-free balance sheet, and thinks the company could be a buyout target thanks to these qualities. Our CAPS investors might agree, as Tesco vacillates between a respectable four-star rating and a tip-top five stars these days.

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