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 rebel airline JetBlue (Nasdaq: JBLU) plunged as much as 10% after reporting an 18% drop in fourth-quarter profit last night. Soleil Securities downgraded the stock to a hold from a buy following the report.

So what: You just knew airlines couldn't keep winning. After a good but incomplete report from United Continental and a better report from US Airways, JetBlue proved that airlines tend to do poorly when oil prices rise. After labor, fuel is most carriers' second-largest expense.

Now what: Normally, I'm not one for following the herd, but the bears probably have a point here. JetBlue missed consensus estimates by $0.03 per share. Revenue improved 13% to more than $940 million, but according to Yahoo! Finance, analysts were looking for $961 million. In each case, JetBlue missed by a significant margin.

Tempting though it may be to buy on the dip, my advice is to stay in your seat, seat belt fastened, and wait for earnings to complete at least a modest ascent before adding shares to your portfolio.

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

Fool contributor Tim Beyers is a member of the Motley Fool Rule Breakers stock-picking team. He didn't own shares in any of the companies mentioned in this article at the time of publication. Check out Tim's portfolio holdings and Foolish writings, or connect with him on Twitter as @milehighfool. You can also get his insights delivered directly to your RSS reader. 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 also on Twitter as @TheMotleyFool. Its disclosure policy is at least 10% better than other disclosure policies.