Technicals - Dow Jones - potential for a new sell signal to be generated

The Dow Jones originally generated a technical sell signal at 20,668 on 21/3/17.
The index technicals turned negative at that point.
A secondary technical sell signal was generated at 20,453 on 13/4/17.
The potential now exists for a third sell signal to be generated - a close below 20,580 would re-enforce the expectation for a pullback to 19,720.
It has also previously been highlighted that the Dow Jones had been located at the most overbought level on a momentum / RSI basis that since 2007  which was flagged as reason for caution relating to the sustainability of the rally (refer to lower panel on second chart below).(VIEW LINK)
The Dow Jones has also been located at the upper end of the long-term trend channel that originated in 2008.