Sell To Open
A phrase used by many brokerages on the street to represent the opening of a short position in option transactions.
Investopedia Commentary
An investor can sell to open either (or a combination of) puts or calls and thus will be holding the option(s) short. The distinguishing factor of a sell to open is that the option position must not be held long in the account during the transaction.
Related Links
Options Basics Tutorial
The Importance of Time Value
See also: Buy, Buy to Close, Buy to Open, Call, Long, Open Interest, Option, Put, Sell to Close, Short