In the MoonBot terminal, the final results of the report window indicate: “Vol: 171 k$”, what is it?

In the MoonBot terminal, clicking on the Reports button opens a window with reports, below the table with transactions in the final results, the information “Vol: 171 k$” indicates the average trading volume, taking into account the choice of the date and time interval of the report, as well as filters in the Report window.