Charm Regime
The categorical direction of 0DTE / OPEX charm hedging flow.
Definition
A categorical label describing the direction of time-decay-driven dealer hedging flow on a given session, derived from net chain charm and expected close-time flow.
Formula
charm_regime ∈ { time_decay_dealers_buy, time_decay_dealers_sell, neutral }
Positive chain charm + near-expiry concentration = dealers_buy into close. Negative chain charm = dealers_sell.
Inputs
net chain charmtime to expiryOI concentration
Output
charm_regime (string label)
Interpretation
- time_decay_dealers_buy: dealers buy into EOD as delta drifts up. Late-session support.
- time_decay_dealers_sell: dealers sell into EOD. Late-session pressure.
- neutral: minimal charm flow. No intraday directional edge from time decay.
API Reference
Endpoint
GET /v1/zero-dte/{symbol}
Tier
Basic
Response field
charm_regime
Why Charm Regime Matters for Trading
TL;DR
Charm regime labels whether dealers will buy or sell into the close from pure time decay. Peaks in influence on OPEX Thu/Fri afternoons.
- What it measures
- A string label ('time_decay_dealers_buy' or 'time_decay_dealers_sell') summarising the direction of dealer charm hedging for the current session.
- What it signals
- Whether the last-hour tape will lean bullish or bearish purely from dealer hedging of charm.
- Why we measure it
- CHEX is a number. Charm regime is the one-word version that retail and systematic screeners can filter on.
- Who uses it
- 0DTE traders, OPEX specialists, intraday directional traders, closing-auction participants.
How to read Charm Regime
time_decay_dealers_buy
- Dealers buy into the close
- Supports late-session rallies
- Peaks Thu/Fri of OPEX week
- Reinforces pin setups
Good for: late-day longs, pin plays
time_decay_dealers_sell
- Dealers sell into the close
- Pressure on last-hour rallies
- Often from call-OI unwinds
- Fade-rally setups late day
Bad for: late-day longs
neutral
- Minimal charm flow
- Time decay not directional
- Trade on other factors
- Typical midweek reading
No charm edge
Rules of thumb
- Most active Thu/Fri of OPEX. Charm flow peaks as expiry approaches. Midweek regimes are usually noise.
- Effect concentrates in last 60 minutes. Label is useful for closing-auction setups, not the midday tape.
- Pair with CHEX. Regime tells direction; CHEX tells size.
- Weekend charm still matters. Monday opens reflect Friday-evening charm repositioning from 3 days of decay.
- 0DTE amplifies the regime. Same-day expiry makes charm dominate over vanna and vega into the close.
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