Nasdaq trading volume double counted

The trading volume statistic from the NASDAQ is overstated as compared to that of the NYSE and the ASE given the double counting problem associated with the NASDAQ's dealer system (Anderson and of thumb is that NASDAQ trading volume is roughly double-counted compared to NYSE volume. [See also Atkins and Dyl (1997) and Wansley, Daves and Stewart (2002)]. 2 Daily Market Summary. Daily market summary represents volume from all trading venues on which Nasdaq ® Issues are traded. The total trading volume is 3 million shares. The dollar amount of trading equals $12 x 1 million + $12.50 x 2 million, totaling $37 million. In other words, investors handed a total of $37 million to one another while buying Exxon Mobil stock that day.

Nasdaq Global Trading and Market Services at +1 800 846 0477; Nasdaq Global Data Products at +1 301 978 5307; Data represent share volume of Nasdaq-listed, NYSE-listed or U.S. equity securities (including ETFs) that are executed on the Nasdaq, BX and PSX books as a percentage of consolidated market volume. Data are single counted.

The volume is presented as double counted to represent that each trade reported to Nasdaq for clearing is replaced by two new trades once the original trade has been novated and Nasdaq replaces the original buyer towards the seller and vice versa. The Open Interest is presented as single counted The Investor Relations website contains information about Nasdaq, Inc.'s business for stockholders, potential investors, and financial analysts. Trading Volume: NASDAQ and the NYSE Anne M. Anderson and Edward A. Dyl Historically, reported trading volume has been overstatedfor NASDAQ stocks relative to NYSE that NASDAQ volume may be double-counted, so they frequently use an adjustment fac-tor of 50 percent or so to make NASDAQ volume comparable to NYSE volume.1 However, times NASD spokesman Mike Shokouhi says that, besides these "riskless principal" trades, there's really no difference between how the Nasdaq and the NYSE count volume. All trades made by Nasdaq market

ing the reported trading volume by dividing the reported volume by two. Such an adjustment may be necessary because reported trading volume on the Nasdaq exchange may be double- (and even triple-) counted, since Nasdaq is a “dealer market.” In a dealer market, transactions from buyer to seller pass through a dealer and are thus double-counted.

been overstated for NASDAQ stocks vis-a- vis NYSE stocks. Market practitioners know that NASDAQ volume may be double- counted, so they frequently use an