I'm learning this as I trade ETFs trying to prepare for the YM and ES. I've held on to some DXD way too long (since mid-August), and I held on too long the last two days in my intraday trading as well.
I had 9 positive intraday trades yesterday: +$331.87, +$1.80, +$70.33, +$136.83, +$289.09...