Section 03 · Charm · the clock

Charm —
the gravity of the close

Charm is the quiet one. It's hedging driven purely by time passing — no price move, no VIX move, just the clock ticking toward expiry. It's why afternoons on expiry days pin to a magic number, and why the morning playbook stops working after lunch.

03.1

What charm actually is

Charm is how a dealer's hedge drifts as time passes, with everything else frozen. Options lose value to time decay every minute; as they decay, the dealer's hedge slowly becomes wrong, so they trade futures to correct it. Near expiry that correction concentrates around the biggest strikes — and price gets dragged toward them.

In one sentence
How dealer hedging drifts as time runs out
Pure clock effect — independent of price and the VIX.
The key idea
Pin gravity
Price gets pulled to the dominant strike and held there into the close.
Typical charm flow into expiry
Time passes
OTM option deltas decay toward zero
Dealer unwinds the hedge
Price drifts toward the pin strike
03.2

Charm grows through the day

Charm is almost meaningless at 9:30 and dominant by 3:00. That's why the pipeline time-weights it: a multiplier that ramps from ×0.5 at the open to ×1.5 at the close. The same charm reading means very different things at different times.

Time (ET)WeightWhat it means
09:30×0.5Charm muted — trade gamma normally, ignore the pin.
12:00×0.93Charm waking up — start filtering trades toward the pin.
15:00×1.36Charm dominant — pin drift is the trade.
16:00×1.50Maximum pull — exits only.
The Friday bump: on Fridays the weight gets an extra ×1.25. Weekly expiry stacks the most decay into that session, so Friday afternoons pin the hardest of the week — and OPEX Fridays (the monthly 3rd Friday) hardest of all.
03.3

The charm clock

Every expiry day runs the same arc — gamma in the morning, charm in the afternoon. This is the session structure to keep on your desk:

9:30 AM
GEX dominant. Trade ramps and flip levels normally. Charm present but weak.
11:00 AM
Identify the pin strike now. Start filtering trades toward it. GEX still primary.
12:00 PM
Charm accelerates. Reduce gamma-level trades. Only take entries aligned with the pin.
1:30 PM
Charm dominant. Pin drift trade active. Fade everything moving away from the pin.
3:00 PM
Maximum pin gravity. Exits only — no new entries after this.
3:30 PM
Exit all charm trades. Gamma expires, the stabilizer is removed, unwind risk begins.
The hard rule on Wed & Fri: switch at 12:00. Your morning gamma-level reactions become unreliable after noon — charm takes the wheel. Traders who keep fading gamma walls into the afternoon get ground up by the pin drift.
03.4

The pin strike & your two charm levels

Charm produces two of your nine levels — and one all-important target, the pin strike.

Pin-strike recipe
Largest absolute gamma strike within ~1% of price
+ a round or semi-round number (7300, 7350, 7400)
+ already tested twice and held intraday
= high-probability charm pin target
Charm pin
Positive charm — decay forces dealer buying → a stabilizing magnet. Price is pulled to it and held.
Charm fade
Negative charm — decay unwinds the hedge → a directional push. Pushes price away, doesn't hold it.

Full play-by-play on both — edge cases, scenario trees and all — lives on the Levels page.

03.5

The charm-drift read

Besides the two levels, the pipeline computes a single board-wide charm tilt — is the day's decay flow pulling up or down, and how hard? You'll see it in your Discord post and the indicator's info table as a small arrow:

#CHXDRIFT ▼ DOWN · heavy — charm decay pulls lower into a negative-gamma board below the flip; drift and regime align, so fade-the-rally pressure compounds into the close. First real support is the trapdoor below — lose it and charm and dealers both sell the break. Background tilt, not a trigger.
How to use the drift: it's a background tilt, the weakest of the three forces. When it aligns with the gamma regime it compounds the move into the close; when it opposes the regime it just fades and doesn't lead. A gamma-flip break or a news event always overrides it.
Primary source: charm time-weighting and the drift algorithm are codified in the gexgreeks skill. For the theory of expiry pinning, read the academic work on "option expiration and stock pinning" (Ni, Pearson & Poteshman) and SpotGamma's charm/pinning notes.