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 Tremor Video Inc. (NYSE:TRMR) initially popped more than 10% Monday morning following Friday's harrowing 49% post-earnings plunge, then fell back into negative territory as the day's trading wore on.

So what: Last week's disappointing quarterly results and weak forward guidance were bad enough to spur no less than three analyst downgrades, but I already stated at the time I wasn't convinced Tremor Video's punishment fit the crime. Given Friday's massive drop, then, this morning's subsequent bounce should come as no surprise.

Now what: Even so, that shares couldn't maintain the rebound shows investors are obviously still skittish with regard to Tremor Video's long-term prospects. To be sure, it's difficult to blame anyone for wanting to stay on the sidelines until Tremor can prove its current weakness is only temporary.

Fool contributor Steve Symington owns shares of Apple. The Motley Fool recommends Apple. The Motley Fool owns shares of Apple. Try any of our Foolish newsletter services free for 30 days. 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 has a disclosure policy.