The Monthly Market Summary provide a summarization of activity for a given month. The values are an aggregation of the month's trading statistics specifically: Share Volume, Number of Trades, and the number of positions in NASDAQ securities. The statistics are available for the NASDAQ Market as a whole. Monthly Market Activity data for a given month becomes available approximately on the tenth business day of the following month. 
  Month: Nov 2012
        Trades % of Trades Share Volume % of Volume     | Block |   15 |   0.00 % |   283,451 |   0.00 % |      | Non-Block |   148,206,636 |   100.00 % |   36,150,557,259 |   100.00 % |      | Total |   148,206,651 |   100.00 % |   36,150,840,710 |   100.00 % |            | Average Daily Share Volume |   1,721,468,605 |      | Average Daily Dollar Volume |   $52,707,512,099 |      | # of Trading Days |   21 |       |            | Total NASDAQ-Listed Securities |   2,740 |      | Total Market Makers |   115 |      | Total Market Maker Positions |   45,824 |      | Average Market Makers/Security |   16.72 |    |