VWAP (Volume-Weighted Average Price) is the cumulative average price a security has traded at over a session, weighted by volume — i.e. the average price at which the day's shares actually changed hands. It was built by and for institutions as an execution benchmark: a desk filling a large order judges its fills against VWAP (buying below it / selling above it beats the day's average participant). Anchored VWAP (AVWAP) is the identical calculation, but instead of resetting at the session open it begins from a user-chosen significant bar — an earnings gap, a swing high or low, an IPO's first print, an FOMC bar. Popularized by Brian Shannon (CMT), AVWAP reframes the tool from an intraday execution yardstick into a multi-session "running cost basis since event X." The core tension: VWAP is a rigorously useful measurement of execution quality, but its use as a directional signal — and especially AVWAP's predictive edge — rests on intuition and chart-reading, not on published, measured base rates.

How it's calculated

For each intraday period, compute the typical price = (High + Low + Close) / 3. Then maintain two running (cumulative) totals from the anchor forward:

VWAP = Σ(Typical Price × Volume) / Σ(Volume)

— the cumulative sum of (typical price × volume) divided by the cumulative sum of volume, recomputed each bar (StockCharts ChartSchool; Wikipedia). Two properties follow directly:

• Cumulative & path-dependent. Each new bar adds to both totals; the line stabilizes through the day because the divisor (total volume) keeps growing, so late bars move VWAP less than early ones. It therefore lags price.
• The anchor defines everything. Standard session VWAP anchors at the day's open and resets each session (it is undefined on daily/weekly/monthly bars — it needs intraday data). AVWAP simply moves the anchor to a chosen bar and never resets until you re-anchor, so it can span weeks or months. Some implementations use Close rather than (H+L+C)/3 as the price input; the weighting and anchor matter far more than that choice.

How it's used in practice

1. Execution benchmarking (its original, undisputed job). Institutions break large orders into slices throughout the day and aim to fill at or better than the day's VWAP; VWAP is one of the standard transaction-cost benchmarks (alongside implementation shortfall and arrival price). This is measurement, not prediction — and it is what VWAP is genuinely authoritative for.

2. Intraday fair-value / mean-reversion reference. Day traders treat session VWAP as the day's "fair value": price stretched far above it may revert down toward it, far below may revert up. Above an up-sloping VWAP, intraday buyers are deemed in control; below a down-sloping VWAP, sellers.

3. Dynamic support/resistance. Both VWAP and AVWAP act as moving S/R levels: price often pauses, bounces, or rejects at the line, and a level that was resistance can flip to support once reclaimed (Shannon/Alphatrends). Because AVWAP encodes the average cost basis of everyone who bought since the anchor event, reclaiming it / losing it is read as the marginal holder moving into profit or loss.

4. Anchored cost-basis and multi-anchor confluence. The swing-relevant use is AVWAP anchored to a meaningful event — earnings gap, breakout, IPO, major high/low — to track whether buyers from that event are collectively winning or losing. Traders plot several AVWAPs from different anchors; where multiple lines converge, that price is treated as a higher-conviction S/R zone. The anchor choice is, in Shannon's own words, "the most subjective part of the analysis."

Standing & evidence

VWAP-as-benchmark is institutionally entrenched — a very large share of US equity volume is worked through VWAP-targeting execution algorithms, and VWAP is a textbook transaction-cost-analysis benchmark. That standing is about execution quality measurement and does not, by itself, validate VWAP or AVWAP as a directional signal.

On the signal side, intellectual honesty matters: AVWAP is intuitive, widely adopted since charting platforms added it, and rests on a sound premise (cost basis matters). But its predictive edge is largely untested in the public literature — the case for it is built on chart examples and practitioner reasoning, not on Bulkowski-style measured hit rates or peer-reviewed studies. Treat "price respects this AVWAP" as a plausible heuristic, not an established base rate. Self-confirmation is a real risk: with enough candidate anchors, some line will appear to "work" in hindsight on almost any chart.

Strengths & limitations

Strengths. Objective and reproducible (no tunable period like a moving average); volume-weighted, so it reflects where trade actually concentrated; AVWAP gives a defensible read on post-event cost basis that a simple SMA does not.

Limitations & misuse.

• Session VWAP is an intraday tool and is essentially irrelevant to multi-day/swing horizons — it resets every day. The swing-relevant variant is AVWAP anchored to a key event; do not apply intraday VWAP logic to a swing chart.
• It lags and is path-dependent — it describes where trading has been, not where it's going.
• #1 misuse: anchor cherry-picking. Because results are entirely contingent on the chosen anchor, it is easy to retro-fit an anchor that "explains" recent price and then over-trust it. Anchors should be chosen by a fixed rule (the relevant earnings, the obvious swing pivot), pre-trade, not hunted for after the fact.
• Confluence ≠ confirmation. Multiple AVWAPs converging is suggestive, not a measured edge.

System relevance

This node is the volume/order-flow definition of VWAP and AVWAP. The swing-specific operational mechanics — exactly which event to anchor to for a given setup, where to place entries/stops relative to an AVWAP, and hold logic — live in the Swing Trading branch; this doc defers those there rather than duplicating them. For Delvantic's Augustus trade-setup agent, the hard caveat to carry forward is the separation above: VWAP is authoritative as an execution benchmark and as objective context (post-event cost basis, intraday fair value), but any directional weight placed on AVWAP S/R is a heuristic without measured base rates — so it should inform, not decide, and its real-world hit rate is for Cairn to measure rather than to assume.

Sources

• StockCharts ChartSchool — Volume-Weighted Average Price (VWAP): formula Cumulative(Volume × Typical Price)/Cumulative(Volume), typical price = (H+L+C)/3, session-reset and intraday-only behavior.
• Wikipedia — Volume-weighted average price: formula, institutional execution-benchmark origin.
• Brian Shannon (Alphatrends) — Anchored VWAP; Maximum Trading Gains With Anchored VWAP (2023); CMT Association — Shannon, "Specific Anchored VWAP Strategies": AVWAP definition, anchor selection, dynamic S/R, "most subjective part of the analysis."
• Corporate Finance Institute; Charles Schwab — VWAP as execution benchmark / transaction-cost analysis.
• Note on evidence: searches surfaced extensive practitioner material on AVWAP but no measured base-rate or peer-reviewed test of its directional edge — flagged as untested in the doc rather than asserted.