Was it skill, dumb luck—or something more sinister? That's what traders are asking about a big, longshot bet on Sodastream that returned some 3,000 percent in just two hours.
Two minutes before 10 a.m. ET on Thursday, one options trader bought 500 weekly 30-strike calls in Sodastream for 15 cents each (or $15 per contract, given that each contract controls 100 shares) that expire Friday. It was by far the biggest Sodastream trade of the day in terms of the number of contracts. The purchase gives the trader the right to buy Sodastream shares for $30 at the close of Friday trading. The reason those options were so inexpensive is that the stock was trading at about $29.50 at the time, meaning the chance of the stock closing Friday above $30 was considered to be especially low.
But then, shortly before noon, Bloomberg reported that the company is in talks with an investment firm about taking the company private. After a halt, the stock sailed as high as $36.
The news created an instant windfall for the trader, as these options, which were bought for $7,500, became worth as much as $250,000.
"Prior to the halt, calls had already traded more than two times their average daily volume," commented Dan Nathan of RiskReversal.com. "The fact that the most active option of the day was an out-of-the-money call that expired tomorrow suggests someone knew something, as there were no scheduled events."
The trade, which could end up drawing insider-trading-related scrutiny, joins other recent suspicious options trades, such as the "fishy" action in Puma Biotechnology ahead of that company's announcement of positive test results.
Correction: This article has been updated to reflect the reason the Sodastream call options were so inexpensive.
—By CNBC's Alex Rosenberg