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: Oil and gas operator HyperDynamics (NYSE: HDY) threw its shares into reverse today, gently lowering its going price by 10.1% on average trading volume.

So what: Last Friday's 10.4% spike didn't last, and for no good reason. There is no news of any kind on HyperDynamics itself today, though rival (and much larger) oil and gas explorer Forest Oil (NYSE: FST) just reported disappointing earnings.

Now what: HyperDynamics stock has quadrupled over the past six months and nearly doubled in three, and the gains didn't last long when HyperDynamics climbed above the current levels in January. It's not surprising to see skittish investors in such a fast-moving and unpredictable stock taking some profits off the table on the lightest of negative news, especially after a gain like Friday's.

Interested in more info on HyperDynamics? Add it to your watchlist.

Fool contributor Anders Bylund holds no position in any of the companies discussed here. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool is investors writing for investors.