$UAA calls double in hours

Option traders who opened bullish positions in Under Armour (UAA) this morning were posting large profits by the afternoon.

Less than 10 minutes after the opening bell, our tracking systems found that 1,900 Weekly $19.50 calls expiring this Friday were bought for $0.19 to $0.22 above open interest of 282 contracts with shares at $19.28. Market Rebellion co-founder Pete Najarian cited the unusual activity on CNBC’s “Halftime Report” today.

Volume in those calls swelled above 8,300 by early afternoon as those calls traded for as much as $0.44 so far today, at least twice their purchase prices. The stock rose 1.87% at the same time, underscoring 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.

UAA is up 2.87% to $19.56 entering the final hour of trading.