A bull spread is a type of call option that aims to profit off of a underlying security that has a specified percent increase. Most of the time investors aim for moderate or low price increase.
An example of a bull spread is to buy a call option for Apple for a expiring three months from now for a strike price of $130 per share. Apple trades at $113.99 as of right now (premarket 12/29/2014). The call option costs $1.37 market price, so for a single option you will be paying $137 (options come in stacks of 100). If you wanted to lower that cost all you’d have to do is sell another call option for Apple for say $140. You’ll get 50 cents for this, so you’ll lower your total cost for this “play” to 87 cents. So pay $87 rather than $137 to make at MOST $10 per share, or $1,000.
I personally am not a fan of the bull spread because of the fact that you’re limiting your winnings, it’s like buying insurance on your winnings. I must prefer having unlimited UPSIDE potential with a put option in place as INSURANCE. Even so, when you’re hedging your investments you are limiting your profit potential.
You can also do what I call a “bear spread” by buying a put option and then selling a put option for a even lower strike price. This would be in anticipation for a moderate downfall in the price of an underlying security. I would personally never do this, it would almost take a wizard or oracle to predict such a price fall to such a degree. You’re better off shorting a stock then paying such hefty premiums for these options.
If you’re interested in seeing what a bull spread looks like on a profit-loss graph here it is below: