Trading Plan: S+P and Dow trading rules

The closing price of the S+P index is very important:

ideally I go short at a prior closing price

or long at a prior closing price

if the market opens above prior day high its and outside gap up, in that case I try hold on the long trend but usually there will be a sharp move down followed by a rally to 50% of the last down move then I short

if the market opens inside the range of prior day but much higher than the close I am looking for short setups to fill the gap

vise verse for if the market opens below prior closing price.

On the dow its wise to simply go long till the end of the session if the market opened above prior days 50% line: