A call spread is a bullish option strategy involving buying one call option at a lower strike price and simultaneously selling another call option at a higher strike price with the same underlying asset, expiration date, and quantity.
Traders use call spreads to speculate on the limited upside potential of the underlying asset while limiting their risk and maximizing their potential profit. By simultaneously buying and selling call options, the trader defines a range within which they expect the asset price to fluctuate.