By looking at last 1 year chart, SPY is try to pass ATH (meaning pass ATH more than few percent) but it failed twice. Now it is third time and failure rate/sucess rate is 50/50 to my point of view. I do understand that we are still in Bull market and bet on bull is more chance to win at any given day but I will be extra carefull at this level. It is just nothing more than precaution^^