Analyze opening gaps in index futures. Document if they fill and when they fill. Watch the first 30 minutes.
If the gap fills early, was there a reversal back in the direction of the gap?
If the gap remained open until the PM session, did it fill late in the day?
Did it fill the next morning?
Did it fill near the end of the week?
What percentage of the time did the gap fill in the same day?
Can you use this to your advantage?