Rooted around and found this chart by Katusa research after watching the Gartman interview.
Did a quick eyeball and from the 1973/1974 (oil crisis) peak to the 1990 (gulf crisis) peak was about
16 years. And from the 1990 (gulf crisis) peak to the 2008 (Global Financial crisis) peak was about 18 years.
Wow, lots of cris-eyes.
From the 1971 (dot.com bubble) low to 1987 low was about 16 years. And from the 2000 (tech bubble low) to
the current 2017 lows is about 17 years. Hmmmm maybe he is onto something as Jeff Glomberg said in
the movie Independence Day - "Times Up". Didn't Gann say time is more important than price???
Of course I think the S&P 500 Commodity Index they are using is the GSCI which is the Goldman Sacks Index,
but I am not sure about it or the weight of the commodities it tracks.