Trading range

Here is a five minute bar chart of the e-mini day sessions. I shorted one unit at 911.25 after the market had rallied a little more than it did late Friday (purple rectangles). I am betting that the market will return to the low of its recent trading range (red rectangle) before it retraces more than 1/2 of its move down to this morning's low (red dashed line). That said, I shall reverse my position if the e-minis show strength above that 1/2 point.

I don't think this break is the start of a bigger reaction. My reason? Volume this morning has been moderate, visibly lower than on the last break on May 7 which began this trading range.