Compare
Stack Signal vs. Volume delta
Volume delta (tape delta) is executed volume: buys minus sells. That is Aggressive Flow in our decomposition — one of two components, not the headline.
Stack Signal
Passive plus aggressive
Total Flow includes the book changing underneath the tape, not only what already traded.
- Passive Flow: resting liquidity stacked (+) or pulled (−)
- Aggressive Flow: the classic tape delta
- Total Flow = both, exactly, on every event
- σ-normalized so readings compare across symbols
Volume delta
The tape alone
Delta is useful. It is also incomplete: a book that is quietly pulling bids while delta looks quiet is a different market.
- Counts aggressive executions only
- Misses stacks and pulls at the rest of the book
- Raw contracts do not compare across symbols
- A quiet tape can hide a thinning book
FeatureStack SignalVolume delta
What it measures
Aggressive executions (tape)
Yes
Yes
Passive stacks and pulls
Yes
No
Exact Total = Passive + Aggressive
Yes
No
Readability
σ-normalized across symbols
Yes
No
Honesty
Never smoothed or repainted
Depends on the delta implementation.
Yes
Partial