Quote Originally Posted by f35c View Post
Mike you're right IBD's correcting the volume to the figure you've found on the NASDAQ site. After looking again, this does not match the correct number for the NASDAQ Composite (Tape C), perhaps a change since moving to a new data source for the NASDAQ Composite chart on investors.com. The figure displayed on the nasdaq.com link you gave is TAPE A+B+C, which is not the volume for the NASDAQ Composite.

It's confusing because NASDAQ actually facilitates trades in NYSE listed stocks (TAPE A) and old AMEX stocks + ETFs (TAPE B) plus NASDAQ listed stocks (TAPE C). When the NASDAQ boasts of it's volume it's actually talking about how many TAPE A,B,C trades take place either on it's exchanges or facilitated by it's Trade Reporting Facility TRF. This is NOT the NASDAQ composite volume, which is the volume of NASDAQ listed stocks on all venues / TRFs -including NASDAQ's, which is only TAPE C.

Check out this link for more answers, and perhaps PM me if you have any interest to know more.
http://www.wsj.com/mdc/public/page/2....html#nysevolA

Thanks for helping me understand this. I brought the volume anomalies to IBD's attention, they are now evaluating a change to Tape C NASDAQ volume for the NASDAQ composite chart.