• by Joe Mandese  @mp_joemandese, October 22, 2015

Madison Avenue’s trading volume climbed nearly 17% in September -- reaching its highest point ever for the month, according to the latest installment of the Ad Market Tracker, an index developed by Standard Media Index and MediaPost to track the supply-and-demand of the U.S. ad marketplace.

The index rose 20 points from a 180 in August (typically the lowest-volume month of big agency trading during the year) to a 210 in September (when Madison Avenue spending begins ascending going into the fourth-quarter holiday shopping season).

Significantly, this September was up 12 points over 2014 -- the last high for the month -- and has been steadily climbing since SMI began benchmarking it in 2009. September’s index value has climbed by nearly two-thirds (63%) between 2009 and 2015.

While most media appeared to be ascending in September, not all media grew equally.

Digital media, not surprisingly, grew the fastest -- rising nearly 29% to an index of 622 in September 2015.

National TV, however, actually declined in trading volume year-over-year, falling to an index of 150 in September 2015 -- down 5% -- from an index of 158 in September 2014. That’s partly attributable to the fact that odd-number years compare to the bi-annual and quadrennial effects of even number years for the TV advertising marketplace, including elections, Olympics, etc.