When was it observed?
The market timestamp belongs to the quote, trade or underlying observation. Open interest has its own date. One label cannot describe all these inputs.
READ THE DATA CLOCK
How live is the chart?
Check the inputs, then the update.
A GEX or DEX heatmap combines options sensitivities, open interest and an underlying price. A Net Flow chart aggregates trades. Their timestamps and update schedules describe different observations.
A page refreshed every minute can still contain delayed quotes or yesterday’s open interest. Start with the source timestamps and the selected contracts.
01 / SEPARATE THE CLOCKS
Refresh rate is not data age.
When was it assembled?
The application requests data, validates it and calculates a snapshot. A newly assembled snapshot can contain older market observations.
When did you see it?
The saved result must reach the website and then the browser. Collection, saving, delivery and browser refresh all contribute to the elapsed time.
Follow one quote · invented times, all ET
A new screen does not reset the market clock.
- 01 / MARKET OBSERVATION
The quote is stamped
10:00:20Starting point for quote ageThe option quote and underlying price each need their own timestamp.
- 02 / SNAPSHOT READY
The calculation finishes
10:00:255 seconds after the quoteCollection, validation and calculation happened during this example’s first five seconds.
- 03 / BROWSER DISPLAY
You see the result
10:01:0540 seconds after calculationThe quote is now 45 seconds old. The calculation’s age is 40 seconds. These are different measurements.
What should a useful data label contain?
- Quote and underlying
- Their separate market timestamps
- Open interest
- Reported session date
- Scope and coverage
- Selected contracts; present / expected
- Calculation and delivery
- Method version; calculated and received times
A refresh badge answers only when the page checked for an update. Use the source timestamps to decide how old its inputs are.
02 / FOLLOW THE CALCULATION
GEX and DEX are calculated from inputs.
Delta describes an option’s price sensitivity to the underlying. Gamma describes how delta changes as the underlying moves. Exposure weights those sensitivities by a contract population. These formulas use EasyBear’s current conventions for contracts with a multiplier of 100.
Gamma exposure
GEX = gamma × open interest × 100 × spot² × 0.01 × sign
Units: dollars of delta change per 1% spot move. EasyBear assigns +1 to calls and −1 to puts. This sign convention is an assumption about the exposure book; it does not identify actual dealer holdings.
Delta exposure
DEX = delta × open interest × 100 × spot
Units: signed dollar delta notional. Delta already carries its sign: positive for calls and negative for puts. EasyBear does not apply a second put-side sign change.
Sum the contract contributions over the selected strikes and expirations. GEX dollars and DEX dollars have different meanings. See the worked GEX and DEX calculation for an arithmetic example.
Does someone calculate every update manually?
No. Software can calculate each contract contribution and aggregate the selected book automatically. Human work belongs in validating the inputs, formula, expiry conventions and failure handling. A provider may supply Greeks, or an application may calculate them from a pricing model; the method and assumptions should be disclosed.
03 / DISTINGUISH POSITION COUNTS FROM PRICES
Fresh Greeks do not make open interest live.
Open interest counts outstanding contracts. Intraday volume counts contracts traded during the session. Volume alone cannot tell you how many positions remain open, so adding today’s volume to the prior open interest is not a valid replacement for an updated open-interest count.
A repriced exposure estimate
Keep the reported open-interest population fixed, then update spot, time to expiry and Greeks. GEX and DEX can change even when open interest does not.
An intraday inventory model
A platform may use a separate method to estimate changing positions during the day. Comparing it with a daily-open-interest calculation requires understanding that additional model. Similar labels do not guarantee the same underlying quantity.
A smaller refresh interval improves sampling frequency. It does not establish coverage of every contract, continuous observation, or the accuracy of an inventory estimate.
04 / KEEP ABSENCE VISIBLE
A connected line does not fill a missing minute.
A dashed connector can link the recorded values on either side of a gap. The connector is a visual aid: it assigns no trade premium, contract volume or underlying price to the missing times.
Minute net premium
Read each available interval independently. A missing interval is unavailable, not zero.
Running session total
Adding observed intervals produces an observed subtotal. It cannot establish a complete session total when part of the session is missing.
Sampled underlying price
A price recorded alongside an options observation is a sample. Connecting samples does not establish every intervening high, low or price path.
Explore the same trades as a running total and as minute changes. Time aggregation changes the line’s shape without changing those trades.
05 / MAKE THE COMPARISON FAIR
Why can two platforms disagree?
Match the instrument and population
Use the same symbol or option root, session date, expiration set, strikes and moneyness definition. “All loaded” is a dataset scope, not a guarantee of the full options chain.
Match timestamps and units
Check time zones and source ages. Compare minute flow with minute flow, and cumulative flow with cumulative flow. For gamma, distinguish exposure per $1 move from exposure per 1% move.
Match the method
For exposure, compare open-interest dates, Greek calculations, settlement timing and sign assumptions. For flow, compare execution-condition eligibility, quote matching, trade-size caps and cancellation handling.
Check coverage before judging the picture
Inspect a specific timestamp, strike and expiration on both platforms. A smooth chart can be easy to read, but its appearance does not prove equivalent inputs or complete delivery.
06 / CURRENT PUBLIC DASHBOARD
What does EasyBear show today?
The public GEX dashboard is labelled 15-minute delayed. Its exposure calculations use reported open interest and Greeks, with disclosed model fallbacks where provider Greeks are unavailable. Read the dashboard’s Data notes and the selected snapshot’s date, scope and status.
A collection timestamp is not a promise that every input has that age. An investigation of another data source does not change the source serving the published heatmap.
Method reviewed 4 November 2026. This page explains the current public presentation; it does not certify a future feed or promise a trading result.