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 Maidenform Brands (UNKNOWN:MFB.DL) soared 23% today after lingerie rival Hanesbrands (NYSE:HBI) agreed to acquire it for about $548 million.

So what: The all-cash deal values Maidenform at $23.50 per share and represents a premium of 23% to its closing price of $19.09 on Tuesday. Hanes is making the move to widen its range of offerings -- particularly in the shapewear space -- and judging by its own stock's 8% bump today, Wall Street seems pleased with the price it's paying to do it.

Now what: Hanes expects the deal to be accretive within the first year of completion and estimates that it will add $0.60 per share to annual earnings within the first three. "We are looking forward to Maidenform joining the Hanes family," Hanes Chairman and CEO Richard Noll said. "Maidenform has great brands that consumers trust. Combining the complementary strengths of both companies creates a lot of growth opportunities." So while Maidenform's stock is likely as high as it can go at this point, Hanes' newly expanded portfolio and increased scale might be a source of outsize gains going forward.