By Chris McKhann , analyst at OptionMonster

QLogic ( QLGC) has jumped to its highest levels since October, but options traders apparently believe the stock is near the end of its run.

The network systems company Tuesday jumped as high as $14.20, its highest level since Oct. 14, before pulling back slightly. The stock still ended the day up at $14.12, a gain of 18.6%.

The spike was attributed to speculation that QLogic might be an acquisition possibility after rival Emulex ( ELX) became the target of an unsolicited takeover bid from Broadcom ( BRCM). QLogic is scheduled to report quarterly earnings after the market closes April 30.

But at least some traders are clearly pessimistic on the stock's rise, as OptionMonster's systems show active trading at the $15 strike price for May put contracts. More than 3,300 of these in-the-money puts changed hands Tuesday, the vast majority bought in large blocks for $1.40. This comes against open interest of just 55 contracts, so it is clearly new buying.