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 Jazz Pharmaceuticals (JAZZ 2.56%) soared 10% today after the specialty biopharmaceutical company agreed to acquire Italy-based rare disease drug developer Gentium for $1 billion.

So what: The all-cash deal values Gentium at $57 per share, representing a premium of just 2% to its closing price on Thursday. Jazz is making the move to gain access to Gentium's rare-disease portfolio -- particularly lead drug Defitelio which received European approval in October -- and judging by today's big jump, Mr. Market is thrilled with the price that management is paying to do it.

Now what: Jazz expects the transaction to be immediately accretive to its adjusted earnings per share. "Incorporating Gentium into Jazz Pharmaceuticals is a strong strategic fit as Defitelio would diversify our development and commercial portfolio and complement our clinical experience in hematology/oncology and our expertise in reaching targeted physicians who treat serious medical conditions," said Jazz Chairman and CEO Bruce Cozadd. "Because Defitelio is already approved in the EU, the acquisition would add a new orphan product that has potential for short- and long-term revenue generation, high growth and expansion of our multi-national commercial platform." So while Gentium is likely all popped out at this point, biotech savvy Fools might want to look into Jazz's newly bolstered portfolio.