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: What goes up, must come down. Last week, investors in Newpark Resources (NYSE: NR) cheered as a successful earnings report drove their stock up 14%. Today, the long arm of the Law of Gravity reached out and pulled Newpark back down to earth -- an early 10% drop that's mercifully morphed into "only" an 8% decline.

So what: Aside from someone flipping gravity's "on" switch, was there any good reason for Newpark to drop today? Well, there's the valuation of course. At 19 times earnings, Newpark's no longer the bargain it was a few days ago. An 11% growth rate, and no dividend to support it, meant Newpark was always going to have trouble holding onto its gains.

Now what: While you might not think it, it probably doesn't help matters that yesterday, Capital One Southcoast decided to upgrade Newpark shares to "add." If Newpark's stock was pretty pricey already, postearnings, and postprice-run-up, probably the last thing shareholders needed was a vote of approval from one of the worst oil analysts on the planet.

Sorry to say this, Newpark investors. But if Capital One likes your stock, I don't.

Can it be true? A mere Fool right, and a mighty investment banker wrong? Add the stock to your watchlist today, and see how this contest plays out.