Dow Jones recently slightly breached an important resistance level and we currently trade in the area where it can become a false break or a real breakout. Upside momentum fading here would suggest we're likely to see some downside move. A very sharp break from here and a strong down trending move would give the possibility of this turning into a far larger fall and this being a significant high point for the Dow Jones.
As well as us breaking back under the resistance and this implying a failure to hold a breakout, we've also seen the break of a near term trend line. If we break the longer term trend linee we'll probably do so with momentum. If we see this strong selling it will invite us to short more of the Dow.