Cabot Tides Goes To Sell

The Cabot's Tides system has issued a sell signal as of today as 3 of the 5 indexes followed in the Tides are below their respective 50demas and the emas are down at least two consecutive days.  You can learn more about their system at Cabot Tides. Cabot called the market in correction a couple of days ago based on this and other indicators they use.  However, they do not use the system to trade index ETFs as I am doing here.  Also, I have found that there interpretation of the system is sometimes off from mine by a couple of days.  Do they calculate their ma's differently?  I don't know.  In any case the system works.  It is easy to follow, does not produce a lot of whip saws and trades only a few times a year.