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 biotechnology company Elan (NYSE: ELN) sank as low as 12% in intraday trading Wednesday on above-average volume.   

So what: After a bad morning, the shares have steadily recovered along with the S&P 500, so Elan shareholders can breathe at least a small sigh of relief. The shares are down only about 3% at the time of publication, but remain up a whopping 80% in 2011.

Now what: I'd continue to keep the stock on my watch list. Without any company or industry specifics driving today's volatility, the bull case for Elan -- which centers on the exciting growth prospects of its Multiple Sclerosis drug Tysabri -- remains fully intact. In fact, a Seeking Alpha article this morning suggested that biotech biggie Biogen Idec (Nasdaq: BIIB) is particularly hungry for that kind of potential, making Elan a tempting takeover target to boot.

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