Limits on short selling
Participants who want to carry out short selling transactions must comply with certain limitations to this type of operations.
At the time of a short sale, the participant must ensure that the aggregate value of the account's holdings (market value of portfolio securities plus cash balance) is at least double its short positions ( market value of short securities in the portfolio). This calculation must be made taking into account the effect of the proposed transaction. (See an example of application of this rule)
In addition, when a participant has one or more short positions, this affects their net cash balance, which limits their ability to use their cash balance to make purchases with the exception of money market funds. (See the section on buy orders)