Bulls double money in $VST

Traders have been winning in Vistra Energy (VST) for months, and today is no exception.

On Aug. 30, Market Rebellion’s activity scanners identified the purchase of 5,000 January $26 calls bought for $1.10 as part of a bullish roll with shares at $24.93. Open interest in the strike was a mere 50 contracts before the trade occurred, showing that this was a new position.

Those calls have traded for as much as $2.40 so far today, more than twice their purchase price. The stock rose 10.11% in the same time period, illustrating the kind of leverage that can be achieved with options.

Market Rebellion co-founder Jon Najarian cited even more unusual activity in the name on CNBC’s “Halftime Report” yesterday.

Long calls lock in the price where a stock can be purchased, gaining with a rally and providing leverage to the underlying shares. The contracts can quickly lose value if the stock stalls or pulls back but also carry less risk than owning the shares themselves.

VST is up 1.7% to $27.46 in late-day trading. The utility company has been climbing since reporting quarterly results in early August.