The percent gain or loss of the value of the investment or portfolio:

The end value is the value of the investment or portfolio on the ending date range. The beg value is the value of the investment or portfolio on the beginning date range. This figure is not necessarily an indication of performance, as purchases will increase the calculated value. The value does measure the rate at which your investment or portfolio is increasing in value. This field is labeled as %Gain-V.

Note on Short Positions:

The absolute value of beg value is used in the denominator to provide meaningful values for short positions.