Kamek,
Sounds like you are trading to NOT lose instead of trading to win. This is a big hurdle to overcome for most traders including myself.
As long as you have proper position size, a stop on SPY above the HOD is not a lot of money to lose if you get stopped out.
After you get a big 5min down bar in your favor like at 11:25ET, it would be okay to move your stop to breakeven.
Also, notice how the market couldn't get SPY back above 128. I use round pyschological numbers as stops. I would move my stop to 128.20 (give a little bit of room in case they try to run a few stops)
Right now, if you were to take a long (I'm not) I would setup the trade so that my stop is at 126.80, below the LOD and a round physchological number.
Jag