M&A news has pushed the shares of Delta Air Lines, Inc. (NYSE:DAL - 14.13) into the red, but one options trader is gambling on a long-term ascent for the stock. Specifically, the speculator bought September-dated calls, but then hedged his bets by selling higher-strike calls in the same series.

Around midday, symmetrical blocks of 6,000 contracts traded at the September 16 and 20 calls. Considering this duo of strikes harbors open interest of fewer than 950 calls combined, it's safe to assume the blocks consisted of new positions. The 16-strike calls crossed at the ask price of $0.94, suggesting they were purchased, while the 20-strike calls changed hands at $0.19 -- closer to the bid price, implying they were likely sold. In other words, it appears the speculator constructed a bull call spread for a net debit of $0.75 per pair of options.

Had the investor simply purchased the 16-strike calls, his profit would increase the higher DAL soared above $16.94 (strike plus premium paid) by September expiration. However, if the stock remained beneath the strike, the trader would be out the entire $0.94 per option.

In order to limit risk and trim his breakeven rail, the speculator sold the deeper out-of-the-money calls. Now, the position will profit if DAL topples the $16.75 level (bought call strike plus net debit), and he's risking just $0.75 per pair of calls. But, by hedging this way, the strategist also limited his potential reward. Specifically, the most he can make is $3.25 (difference between strikes minus net debit), no matter how far DAL should muscle north of $20.

At last check, DAL has given up 4.4%, after sector peers US Airways (NYSE:LCC) and American Airlines parent AMR Corporation (PINK:AAMRQ) agreed to an $11 billion merger. The all-stock deal would create the world's largest carrier, though U.S. Senators today announced a tentative hearing on the antitrust implications of the planned union.