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 Catalyst Health (Nasdaq: CHSI) soared more than 18% on heavy volume in early trading after the company agreed to acquire Walgreen's (NYSE: WAG) pharmacy benefit management business for $525 million in cash.

So what: Walgreen nets a nice cash payment as it gets out of a competitive, administratively burdensome business that Catalyst happens to specialize in. If all goes well, the handoff will be completed by June.

Now what: And that's when the money should begin to roll in for Catalyst. The company's volume of prescriptions under management will more than double to 165 million, Reuters reports. Its membership rolls will also more than double, from 7 million to more than 18 million.

There's a lot of profitable growth to come as a result of this deal. Probably a lot more than the 19.5% a year analysts had been calling for before today's announcement.

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