All-Exchange Average: 47.4% Drop in August
September 13, 2012
The results are in.
The all-exchange average for trading volume in August was a drop of 47.4%, according to statistics compiled by the Securities Industry and Financial Markets Association.
It really was no contest.

August was the most active month in all of 2011. August was the least active month in all of 2012.
Here’s how the numbers broke down:
August 2011: 7.6 billion shares a day were traded.
August 2012: 4.0 billion shares a day were traded.
That last number actually rounds up to 4.0 billion. If your house statistician were to get precise, August was the first month in either 2011 or 2012 when the average volume was under 4.0 billion shares.
The exact average: 3,989.97 million shares, according to SIFMA.
The numbers cover trading at the New York Stock Exchange, NYSE Amex, NYSE Arca, the Nasdaq exchanges, the BATS exchanges and the Direct Edge exchanges.
The quick summary:
• NYSE, down 54.0%
• NYSE Amex & Arca, down 66.0%
• Nasdaq, down 38.1%
• BATS, down 46.8%
• Direct Edge, down 47.7%
The comparisons can be downloaded below.
Trading in August 2011 was jacked up by reaction to the first-ever downgrade of U.S. debt, by the Standard Poor’s rating agency.









