Quote from Eight:
I'm embracing the chaos here.. I'll master this thing... but it's stressful trading sim money in real time hours, I need to practice after hours on replay data
Don't cheat yourself. It is like betting on the horses after knowing which one has already won.
If you want to practice, practice in real-time. Write down your bet, entry and exit as if you would trade. Then review the result and learn from your own moves.
I trade the opening everyday. Even when I am on vacation, I would not forego the chance to trade the opening. There are only approx 260 openings in a year. I make about 70% of my total gain from trading the first 30 minutes, and most of the time in the first 5 to 10 minutes alone.
Depends on what you trade. Different stocks behave differently at the opening minutes. I trade only 5 stocks day-in and day-out. GS, SKF, SPY, AAPL, RIMM. I have learned their behaviors at the opening. They almost gap in every opening. Sometimes small, sometimes big. From my experience, gaps are to be faded. Works about 70-80% of the time. The other 10-20%, they just gap-and-go (usually on a Monday, or usually when they break above resistance with the gap or break below support.) And another 10% of the time, maybe, they gap-and-flat - not moving at all. If you find yourself wrong fading the gap and there is no reversal, just close out and flip your position to go with the gap.
Trading the opening is not for the faint-of-heart. Gaps are typically created by amatuers. But it doesn't mean necessarilty they benefit the amatuers. Quite the opposite they benefit the pros.
The key to trading the opening: fade the gap or the quick up/down move (but beware of the 20% chance of gap-and-go). These stocks typically go through a reversal at least once. Sometime twice. But rarely more than twice. For example, AAPL can gap up 1.00 from prior day's close, then immediately drops 2.00 to 3.00 in the first 5 minutes, then reverses back up. Those are great trading opportunities.
Just pull up their charts and study how they behave at the opening. The more you read or experience the opening's seemingly chaotic actions, the more you can get better at trading it.