Delayed market data
Delayed market data is data a source publishes a fixed time after the event, commonly around 15 minutes for free or low-cost options feeds. The delay is a property of the source, separate from the age of the snapshot on screen: a fresh snapshot of a delayed source still describes the market as it was a quarter of an hour ago.
Senzoukria · Glossary · Updated September 2026
Definition
Exchanges license real-time data at a price and allow data older than a threshold to be distributed under different, usually cheaper or free, terms. A delayed source is therefore not broken or slow; it publishes on purpose after a fixed lag. What matters is that the display says so, and that no calculation presents a delayed input as live.
Delay versus age
| Measure | Question it answers | Example |
|---|---|---|
| Source delay | How late does this provider publish events? | About 15 minutes for a delayed options feed |
| Snapshot age | How long ago was the data on screen fetched? | Chain received 2 minutes ago |
| Effective lag | How old is the market state I am reading? | About 15 + 2 = 17 minutes |
Worked example
A gamma level is computed from an options chain published 15 minutes late, while ES has moved from 5,000.00 to 5,020.00 in the meantime. The level reflects positions and prices from when the underlying was 20 points lower, a move of 20 / 0.25 = 80 ticks. For structure, such as where the large strikes sit, this may be acceptable; for the last minutes of a move it is not.
In Senzoukria
The GEX workspace keeps the two clocks apart. Its source chip states the provider's delay: 'ALPACA · 15 MIN DELAY' on the free tier, 'DATABENTO OPRA · ≈15 MIN', 'ALPACA OPRA · REAL-TIME' or 'TRADIER · REAL-TIME' where no delay is declared. Its data chip measures the age of the chain actually displayed from the backend's timestamp. The word LIVE appears only when the chain is timestamped, younger than the stale threshold of 20 minutes and from a real-time source; a delayed source shows 'DELAYED ≈n MIN · chain n min', both numbers side by side. The Databento switches for GEX and options flow carry the '≈15 min behind' mention in their labels.
Common mistakes
- Reading a delayed options level against a live futures price as if both were current.
- Treating a fresh snapshot as live data without checking the source's delay.
- Using delayed data to time entries.
Related
In the same section
- Delta
- Degrees of freedom
- Delta at extremes
- Deflated Sharpe
- Delta bars
- Dealer positioning
- Delta divergence
- Databento
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Frequently asked questions
- Is delayed data useless for trading?
- Not for context: the location of large option strikes or the previous day's structure changes slowly. It is unsuitable for anything that depends on the last minutes of price action, such as timing an entry at a level.
- Why does a delayed source still show a young snapshot?
- Because the snapshot's age measures when your application fetched it, not when the events happened. A chain fetched 30 seconds ago from a 15-minute-delayed source describes the market of about 15 and a half minutes ago.