0DTE tells you which contracts are included: those expiring today. It does not mean real-time data. EasyBear uses 15-minute-delayed snapshots and overnight open interest.
Near expiry, location matters
Gamma measures how quickly option delta changes as price moves. Near expiry, the strongest sensitivity sits close to the strike. An option far from its strike behaves differently.
Price near the strike
Small price changes can move delta sharply. At-the-money gamma rises as expiry approaches, with other inputs fixed.
Price far from the strike
Delta is closer to its limit. As expiry approaches, far-from-money gamma tends toward zero under fixed inputs.
Less time does not mean more gamma everywhere. Spot and volatility changes also affect the result. A large total GEX does not by itself forecast a large price move.
The diagram stops before expiry. It does not draw a finite gamma value at the exact expiry boundary.
Exposure can change without new positions
Consider one fictional strike at 100, with spot at 100, a contract multiplier of 100, call open interest of 100 and put open interest of 60. The model counts calls positive and puts negative. These inputs stay fixed in both snapshots.
Snapshot A
Gamma input: 0.02 for each option
+$8,000Net GEX per 1% spot move
Snapshot B
Gamma input: 0.04 for each option
+$16,000Net GEX per 1% spot move
The exposure doubled; the open interest did not change. The higher number reflects the higher gamma input. It is not evidence that dealers bought more contracts.
Both gamma values are invented teaching inputs. They are not computed from a clock or volatility model, and do not forecast an intraday path. The call-positive/put-negative convention is a position assumption; a long put itself has positive gamma.
Check the arithmetic
Net GEX = gamma × multiplier × (call OI − put OI) × spot² × 0.01.
A: 0.02 × 100 × (100 − 60) × 100² × 0.01 = +$8,000 per 1% move.
B: 0.04 × 100 × (100 − 60) × 100² × 0.01 = +$16,000 per 1% move.
This illustrates the dashboard's existing exposure formula. No new calculation is added to the dashboard.
Why 0DTE and Multi-Day can disagree
0DTE isolates today's expiry. Multi-Day combines the tracked expiry set, including today when present. The same moment can therefore have different totals.
Fictional GEX amounts, all in dollars per 1% spot move.
Once today's contracts pass their model expiry horizon, those contracts leave the included book. A later snapshot can differ because coverage changed, even without a new trade.
A session date and an expiry scope answer different questions. The date identifies when a snapshot was saved; the scope identifies the contracts inside it. The current /gex history panel shows Multi-Day captures. Its date selector does not isolate that date's expiry.
Read the dashboard in four steps
- Check the ticker and timestamp. A fresh page is not the same as a fresh underlying quote. Read the visible snapshot and availability labels.
- Choose Today · 0DTE when available. Read scoped totals and nearby concentrations. Expiry columns can still include later expiries; use their headings.
- Compare with Multi-Day. Check whether later expiries reinforce or offset today's exposure. Compare GEX with GEX, in the same units.
- Watch price at the relevant strikes. Exposure identifies sensitivity, not an entry or a guaranteed reversal. Check the simulated GEX profile separately from current net GEX.
Inspect the SPX structure map → · Inspect exposure by strike →
The dashboard opens with SPX. Confirm Today · 0DTE is available; if it is absent, the page can fall back to Multi-Day. Data is 15 minutes delayed.
What this helps you decide
Use 0DTE to choose which nearby strikes deserve attention and whether a changing total comes from sensitivity or a different expiry set. It does not establish a direction, stop distance, position size or win rate.
Mechanics: Options Industry Council: Gamma. Formula and source assumptions: EasyBear methodology. All examples here are original fictional illustrations.
Frequently asked
What is 0DTE gamma?
0DTE gamma exposure comes from options expiring today. At-the-money gamma increases as expiry approaches for fixed other inputs, while far-from-money gamma tends toward zero. Aggregate exposure uses open interest and the model's position-sign assumption.
Why do 0DTE levels change during the day?
Spot, Greeks, volatility inputs and remaining time can change the calculated 0DTE exposures and levels between snapshots. The model uses overnight OI, so these changes do not measure new intraday dealer positions.
How do you trade 0DTE gamma exposure?
Compare 0DTE and multi-day exposure under their stated scopes and timestamps. This dashboard does not establish an entry, stop distance, position size, pinning probability or trading edge.