What this thing is
The thin strip at the top of the Gamma tab is a Replay Scrubber. It lets you scroll the charts backward through time.
Every 5 minutes during market hours, the platform takes a snapshot of the dealer positioning data. The scrubber lets you load any of those snapshots from the last 30 days. When you drag it left, the Gamma charts re-render with what they looked like at that earlier moment.
How to use it
Hover over the strip to expand it. You will see a thicker bar with a draggable thumb and a few quick-jump buttons.
Drag the thumb left to go back in time. The charts update to show that historical moment.
Quick-jump buttons: LIVE (back to right now), 1h ago (one hour ago), Open (today's 9:30 ET open), Yesterday close (yesterday at 4:00 ET).
Snap-back to LIVE: if you drag the thumb back to within one minute of 'now', it auto-snaps to LIVE. You do not have to be precise.
What is this actually for?
After a big move, you want to know: was the move caused by something structural (dealer hedging hitting a level), or by something discretionary (a big trader, news, a fund flow)?
Scrub back to right BEFORE the move. Look at the Gamma tab.
If the Vol Trigger or Gamma Flip just broke right before the move, the move was MECHANICAL. Dealer hedging caused it. Expect follow-through. Do not fight it.
If nothing on the chart looks different from earlier, the move was discretionary. Expect mean reversion. The move was a one-off event, not the start of a trend.
This distinction is the difference between trading the move and getting steamrolled by it.
When you are in replay mode
The chart shows a small timestamp badge in the top right corner. It tells you the actual moment the snapshot was taken (which might be a few minutes off your requested time, because snapshots are 5 minutes apart).
Live updates pause while you are scrubbed. The chart shows you the historical moment, not the latest data. When you click LIVE, updates resume.
Pro feature
The Replay Scrubber is Pro only. The Gamma tab itself is locked for Lite users.
Things that might surprise you
Cross-quarter compatibility. You can scrub back through the JHEQX collar resets, regime changes, and OPEX expiries from the last 30 days. Useful for studying how a specific event played out.
Friday close to Monday morning. There is a gap. The scheduler does not write snapshots over the weekend. Scrubbing Friday's last snapshot to Monday's first is normal.
Some charts say 'No snapshot available.' If you scrub to a time where no snapshot exists (off-hours, before the platform started recording for that ticker, etc.), you will see 'No snapshot available at this time. Try a later time or click LIVE.' Just hop forward or back.
Conflict with the OPEX projection mode
The OPEX card on the Overview tab has a 'post-OPEX projection' mode that simulates what dealer positioning would look like after OPEX clears. You cannot use that AND replay at the same time. Turning one on automatically turns the other off. They live in different worlds (one is hypothetical future, the other is historical past).