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 online genealogist Ancestry.com (Nasdaq: ACOM) fell as much as 14.1% overnight on heavy volume.

So what: Last night's second-quarter report was just fine, exceeding analyst estimates on both the top and bottom lines. However, the third-quarter outlook was less than enthusiastic, which was enough to send the stock plunging.

Now what: This drop was the opposite of the reaction three months ago, when news of bulging subscriber lists gave the stock an instant 26% lift. All things considered, Ancestry shares still trade some 13% above the levels seen right before that first-quarter update and they have nearly doubled over the past year, so it's hard to get too upset over this correction.

Don't panic. If Rule Breakers investing has taught us anything, it's the value of patience as the market reacts, overreacts, and adjusts to what these unpredictable companies are up to. Even the top performers on that scorecard, such as Green Mountain Coffee Roasters (Nasdaq: GMCR) and Baidu.com (Nasdaq: BIDU), have been through their double-digit overnight plunges and still provide ten-bagger returns (or better) over the long haul.

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

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.