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 Eastern Insurance Holdings (NASDAQ: EIHI) soared 16% today after specialty insurance company ProAssurance (PRA 2.37%) agreed to acquire the casualty insurance company for about $205 million.

So what: The all-cash deal values Eastern at $24.50 per share and represents a premium of 16% to its Monday closing price. ProAssurance is making the move to expand its workers' compensation coverage, and judging by its own stock's flat action today, Mr. Market seems OK with the price management is paying to do it.

Now what: ProAssurance expects the deal to close by the end of the year and be accretive to its 2014 earnings. "Eastern has a strong, long-term position in health care workers' compensation that will allow us to broaden the high quality products we are able to offer our existing customers," said ProAssurance Chairman and CEO W. Stancil Starnes. "Equally important is the product line diversification the transaction will provide for the combined organization." So, while Eastern is likely all popped out at this point, ProAssurance's newly bolstered coverage and diverse offerings might be worth looking into.