Some thoughts on the VOLUME of SPX

٧ أبريل ٢٠١٩

I've noticed on the SPX Monthly chart, that the volume has been ascending all the way to the 2007 financial crisis correction and after that, the stock market made a new high until recently on a descending volume. I don't know what this exactly means or does it mean something at all but I will appreaciate any comments and thoughts on this. Thanks.SPX