What happened

Shares of Itamar Medical (ITMR) were skyrocketing 44.5% as of 10:48 a.m. EDT on Monday. The huge gain came after Zoll Medical, which is owned by Japanese materials science company Asahi Kasei (AHKSY 0.45%), announced plans to acquire Itamar for $538 million. 

So what

The price tag of Zoll Medical's proposed acquisition reflects a premium of 50% over Itamar's share price as of the market close on Friday. Today's big move for the healthcare stock is only slightly lower than that level.

A person drawing a large fish with its mouth open near a small fish.

Image source: Getty Images.

While the deal is obviously great news for Itamar shareholders, it also seems like a good one for Zoll Medical. Itamar makes medical devices that help diagnose respiratory sleep disorders. Zoll focuses primarily on medical devices and software related to cardiopulmonary issues.

It's estimated that around 60% of cardiovascular patients have some type of sleep apnea. The addition of Itamar's WatchPAT home sleep apnea device should be a great fit with Zoll's product lineup.

Now what

The boards of both Itamar and Zoll have approved the transaction, but the deal isn't done yet. Itamar shareholders must approve the acquisition, and regulators must give their blessing. However, the companies expect that the transaction will close by the end of this year.