The short strangle is a neutral-outlook options trading strategy that involves the simultaneous selling of a slightly out-of-the-money put and a slightly out-of-the-money call of the same underlying security and expiration date. It is a limited profit, unlimited risk strategy that is taken when the options trader thinks that the underlying stock will experience little volatility in the near term. The short strangle is a credit spread as a net credit is taken to enter the trade. The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ...
References
McMillan, Lawrence G. (2002). Options as a Strategic Investment, 4th ed., New York : New York Institute of Finance. ISBN 0-7352-0197-8.