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 biopharmaceutical company Amarin (Nasdaq: AMRN) surged a staggering 80% today on positive results for its fish oil heart disease treatment.

So what: In a late-stage clinical trial, Amarin's lead product candidate, AMR101, was effective at reducing triglycerides without increasing LDL cholesterol, or "bad cholesterol," after 12 weeks. Lovaza -- GlaxoSmithKline's (NYSE: GSK) triglyceride drug which can raise LDL levels in some patients -- managed to bring in $900 million worth of sales last year, so it's no surprise that Mr. Market is extremely excited about AMR101's potential.

Now what: Amarin seems like an interesting situation for speculative investors. AMR101 continues to display clear benefits over competing triglyceride drugs, making it an increasingly tempting takeover target. It's hard to believe, but even with today's 80%-plus surge, Amarin might still be a steal for a patent cliff-facing drug giant.  

Interested in more info on Amarin? 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.