The price was overbought (i.e. interacting with the upper standard deviation channel) on Daily, H4, H1. The break of previous support which turned into resistance on the lower timeframes (15min and 5min) gave enough premise to short.
Stoploss placement above previous lower highs from the higher timeframes. Take profit target at the mean of the standard deviation channel, making this roughly 1:1 reward:risk for initial profit taking.