» Sell an At or Out of the Money call and buy a higher strike call for protection. Since the sold call is closer to the stock price, a credit is achieved. » This is a bearish strategy as you expect the stock to remain below the short (sold) strike price. » An investor wants both options to expire worthless so they will retain the entire net credit. » The maximum risk is the difference between the strike prices minus the credit received.

This strategy is to realize a profit by making cash that is a net credit formed by the difference in a SOLD CALL price and a BOUGHT CALL price. While the stock goes down, the investor keeps the net credit (difference in premiums).
SELL a CALL at or out of the money (lower strike price).
BUY a CALL one or more strikes above #1 CALL in the same month, this provides the upside safety.
The margin requirement is the difference between the strike prices, usually 5 points/dollars.
The maximum risk is the difference between the strike prices, less the net credit (difference in premiums).
The maximum profit is the net credit (difference in premiums).
The break even point is the lower strike price (#1) plus the net credit.
Profit is realized when the stock price falls below this number.
Maximum profit is made when the stock price falls below the lower strike price (#1 CALL).
A profit is realized at any stock price between the break even point and the net credit.

The return calculations for the Bear-Call Credit Spread are:
% Return = (Premium on SOLD CALL - Premium on BOUGHT CALL) ÷ (Margin - Net Credit)
% Return = (Net Credit) ÷ (Margin - Net Credit)
Where...
Margin = SOLD CALL strike price - BOUGHT CALL strike price
Net Credit = Premium on SOLD CALL - Premium on BOUGHT CALL

Example: Stock XYZ at \$90 per share.
Write (Sell) the SEP 100 CALL for \$3.00
Buy the SEP 105 CALL for \$1.85
% Return = (Premium on SOLD CALL - Premium on BOUGHT CALL) ÷ (Margin - Net Credit)
% Return = (3.00 - 1.85) ÷ ((105 - 100) - (3.00 - 1.85)) = 30% if stock is < \$100
Max. Risk = Margin - Net Credit = \$5 - \$1.15 = \$3.85, if stock is > \$105
Max. Profit = Net Credit = \$1.15, if stock is < \$100
Break Even = Lower Strike + Net Credit = \$100 + \$1.15 = \$101.15