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 insurer Protective Life (NYSE: PL) surged 18% today after Japan's Dai-ichi Life Insurance agreed to acquire the company for $5.7 billion.

So what: The widely expected deal values Protective Life at $70 per share and represents a 19% premium to its Tuesday closing price. Dai-ichi is making the move to expand its international presence amid sluggish growth at home; judging by the Japanese company's own 3%-plus pop on the Tokyo Stock Exchange, Mr. Market seems pleased with the price.

Now what: The transaction, which is expected to close by the end of 2014 or early 2015, will create the 13th-largest global insurer, with total assets of $424 billion. "With a strong leadership team, vibrant and growing retail franchise and long track record of profitable growth organically and through the acquisition and integration of attractive businesses, Protective is the ideal platform for expansion," said Dai-ichi Life President Koichiro Watanabe in a press release. "We look forward to working with Protective's management and employees, who will play an integral part in the long-term, continued success of the combined company, to grow our business and build on Protective's commitments to its customers, distributors and the communities in which it operates throughout the U.S." So while Protective Life is likely all popped out at this point, Dai-ichi's newly bolstered scale and growth prospects might be worth looking into.