Usually, the buyer in an M&A transaction has a drop in its stock price. Well, that wasn't the case with Intercontinental Exchange's (ICE) $1 billion purchase of the New York Board of Trade (NYBOT). In fact, ICE's stock surged 10% on the announcement.

Basically, ICE is an electronic exchange for trading on energy products. Despite the recent fall-off in energy prices, the market has been particularly strong for ICE, as the stock has surged almost 80% this year.

So, why not use some of this increased shareholder value to do a deal?

The purchase of the NYBOT will be a move to diversify ICE away from energy. For the most part, NYBOT is an old-school exchange (there is a physical trading floor) that focuses in stuff like sugar, cocoa, and coffee trading.

Also, ICE believes the deal will result in cost synergies of $50 million or so. Something else: ICE is likely to leverage its technology infrastructure into the NYBOT.

Although, according to Wall Street's response, ICE may be too conservative on the benefits of the deal. After all, NYBOT was founded in 1870: there is probably lots of opportunity to modernize things at the exchange.

Tom Taulli is the author of various books, including the Complete M&A Handbook and operates InvestorOffering.com.