What is Delta impact (DEI)?
What Is Delta Impact (DEI)?
Updated 2026-07-21
Quick answer
DEI scales delta exposure by typical stock volume so the same DEX reads louder in a quiet name than in a hyper-liquid one.
Also called: DEI, delta impact.
Visual explainer
DEI scales the same DEX by typical stock volume, so equal exposure reads louder in a thin name than in a mega-cap.
Full definition
DEI asks how loud an options print is relative to how that stock usually trades. Equal DEX is not equal impact across names. Use DEI as a relative impact score for screening, not a precise forecast of the next move.
How it shows up in TradingFlow
- Option Trades
DEI column alongside DEX for cross-symbol impact comparison.
How to read it
- When scanning multi-symbol tape, sort/filter DEI to find outsized impact names.
- Still open chain context, high DEI can be hedges or event positioning.
Who this is for
Multi-name scanners hunting impact in quieter names as well as mega-caps.
Common mistakes
- Treating DEI as a guaranteed move size.
- Using DEI alone without side, DTE, and OI context.
Frequently asked questions
- Is DEI proprietary to TradingFlow?
- DEI is TradingFlow’s presentation of impact scaling (DEX vs typical stock volume). The idea of normalizing exposure is common; the column is part of the Option Trades workflow.
Related terms
- Delta exposure (DEX)DEX estimates share-equivalent directional weight of an options trade, roughly delta × size (with the usual multiplier).
- Option flowOption flow is the time-and-sales stream of options prints: contract, size, premium, and inferred aggressor side.
- Unusual options activity (UOA)UOA flags contracts or underlyings trading far above recent norms in volume, size, or premium. It is an attention screen, not a directional signal.
More guides
See the workflow in TradingFlow
Open the live Option Trades tape, rank unusual activity, and validate structure in one research path.