Yahoo! has recently started adjusting stock's volume for splits. Consequently, your cached historical volume data might be inaccurate. Version 2016.09 is an important update made to the Yahoo! provider which we recommend its every user to apply.

Effective v2016.09, when a new stock split is received by the provider it will download entire historical data of the stock and reverse adjust its cached Volume DataSeries with regard to current and historical splits. What you should see:

1. If split adjustment is NOT activated in provider's settings Wealth-Lab will reverse adjust the cached volume. Historical pre-split volume does not match Yahoo's website by design.
2. If split adjustment is activated (default behavior), adjustment of volume for splits becomes inactive. Historical pre-split volume matches Yahoo's website after reloading data (see below).

To fix any discrepancies between split-adjusted volume coming from Yahoo! and unadjusted volume that may be already cached, it is recommended for Y! data users to refresh their cached histories which is easy to do using the Data Tool extension. First click "Remove all data" on a DataSet and then update it the usual way.