$WU call prices skyrocket 11-fold

Bullish option traders turned enormous gains on Western Union today, just one session after they opened their positions.

On Friday, Investitute’s tracking systems detected the purchase of 3,700 January $20 calls for $0.20 to $0.75 with shares at $20.20. This was clearly fresh buying, as volume was well above the strike’s open interest of 1,382 contracts.

Today those calls traded for $2.25, more than 11 times their original purchase price. The rose 10 percent at the same time, showing how quickly options can far outpace gains in their underlying shares.

Long calls lock in the price where investors can buy a stock, letting them position for a rally at limited cost with the potential for significant leverage. They carry less risk than owning shares because the most that can be lost is the price of the options no matter how far the stock might fall.

WU jumped 4.32 percent to $21.49 today. The stock surged on speculation that the money-transfer service was somehow connected to cryptocurrency Ripple, according to according to Bloomberg.