Which of the following statements is FALSE?

A positive investment in a security can be referred to as a long position in the security.

The efficient portfolios are those portfolios offering the lowest possible level of volatility for a given level of expected return.

It is possible to invest a negative amount in a stock or security (called a short position).

A short sale is a transaction in which you buy a stock that you do not own and then agree to sell that stock back in the future.