on the HD, the break that you chose to short came quite soon after it had already made its largest move down so far that day, so it was a bit of a chase. If you want to look for new lows to short, a breakdown of a sideways consolidation or a double-bottom failure is always a bit safer, with better risk/reward. The break of the "double bottom" between 2:15 and 2:30 (tough to make chart calls on such short time frames) was a much more reliable pattern to short; by 2:45, you already had a volume surge into fresh lows and by that time its really too late.