On this page
Volume Weighted Average Price: The Institutional Benchmark
VWAP is the average price a security has traded at during the session, with each price weighted by the volume that traded there. It is the standard benchmark large institutions use to judge whether their own execution was better or worse than the market average.
Key Takeaways
- VWAP resets at the start of each session and accumulates the ratio of price-times-volume to total volume throughout the day.
- Institutions benchmark trade execution against VWAP: a fill below VWAP is considered efficient, a fill above it is considered costly.
- By afternoon VWAP is so heavily anchored by prior volume that a single bar rarely moves it, late-session price gaps can look detached from VWAP.
- A stock trading above VWAP suggests buyers have been in control for the session; below VWAP suggests sellers have dominated.
Key Takeaways
- VWAP resets at the start of each session and accumulates the ratio of price-times-volume to total volume throughout the day.
- Institutions benchmark trade execution against VWAP: a fill below VWAP is considered efficient, a fill above it is considered costly.
- By afternoon VWAP is so heavily anchored by prior volume that a single bar rarely moves it, late-session price gaps can look detached from VWAP.
- A stock trading above VWAP suggests buyers have been in control for the session; below VWAP suggests sellers have dominated.
What It Is
VWAP is a running intraday average calculated from the opening bell to the current bar. Unlike a simple moving average, it gives more weight to periods with heavier volume and less weight to quiet periods. That makes it a closer approximation to where the "real" trading happened, not just where price printed.
The indicator resets at the start of every session. The VWAP shown at 10:00 a.m. reflects only the trading done that morning. By the close, it reflects the entire day. Because it resets daily, VWAP is primarily an intraday tool, used most often by execution desks, algorithmic traders, and day traders.
The Intuition
If a pension fund needs to buy 500,000 shares over a day, it cares about one question: did I pay more or less than the average participant? VWAP answers that. A fill below the day's VWAP is considered efficient execution; a fill above it is considered expensive. This is why brokers sell "VWAP algorithms" that try to track the benchmark as closely as possible.
For discretionary traders, VWAP serves a slightly different purpose. Because so much institutional flow anchors around it, price tends to react when it touches VWAP intraday. Traders watch it the way they watch a moving average, as a dynamic reference level rather than a standalone signal.
How It Works
The calculation has two running sums that grow through the session. The industry-standard input is the typical price, defined as the average of the high, low, and close of each bar:
Typical Price = (High + Low + Close) / 3
Then, for each bar from the open to the current time:
VWAP = sum(Typical Price * Volume) / sum(Volume)
Variables:
- Typical Price is the midpoint proxy for the price at which the bar traded.
- Volume is the shares (or contracts) traded in that bar.
- Both sums accumulate from the first bar of the session through the current bar.
Because the denominator is total volume so far, early bars with small volume have limited influence. As the session progresses, VWAP becomes "heavier" and moves more slowly. By late afternoon, a single bar rarely shifts it much.
Some platforms offer an anchored VWAP, where you pick the starting bar (for example, an earnings release, a gap, or a swing low) and the average runs forward from there. This extends the concept beyond a single session but uses the same formula.
Worked Example
Assume a stock trades three 15-minute bars after the open:
| Bar | High | Low | Close | Typical Price | Volume |
|---|---|---|---|---|---|
| 1 | 101 | 99 | 100 | 100.00 | 200,000 |
| 2 | 102 | 100 | 101 | 101.00 | 300,000 |
| 3 | 103 | 101 | 102 | 102.00 | 500,000 |
Numerator: (100 * 200,000) + (101 * 300,000) + (102 * 500,000) = 20,000,000 + 30,300,000 + 51,000,000 = 101,300,000 Denominator: 200,000 + 300,000 + 500,000 = 1,000,000 VWAP: 101,300,000 / 1,000,000 = 101.30
Any fill below 101.30 beat the session benchmark so far. Any fill above it paid up relative to the market.
Common Mistakes
-
Using session VWAP as a trading signal without context. A touch of VWAP is not a buy or sell signal on its own. In a trending day price can ride well above or well below VWAP all session. Use it as a reference, and combine it with trend, support, or an execution plan before acting.
-
Comparing VWAP across sessions. VWAP resets every day. Yesterday's VWAP tells you nothing about today's, and a chart that plots prior-session VWAP lines next to the current one invites confusion. If you need a multi-day anchor, use anchored VWAP from a specific event instead.
-
Over-interpreting price touching VWAP. Price revisits the session VWAP on most normal days at least once, simply because VWAP sits inside the day's trading range by construction. A tag of VWAP is often just geometry, not a reversal cue.
-
Assuming VWAP works on any timeframe. The indicator was designed for intraday execution. Applying a "VWAP" over weeks or months stretches the idea past its origins and tends to produce a line that barely differs from a volume-weighted moving average.
-
Ignoring that VWAP lags in the afternoon. By 3:00 p.m., the denominator is so large that even a sharp move barely shifts VWAP. A late reversal can leave the line looking detached from current price action, which is a feature of the math, not a signal.
Frequently Asked Questions
Q: What is VWAP in simple terms? VWAP is the average price at which a stock has traded during the current session, weighted by how much volume traded at each price. It resets at the open every day and builds through the session.
Q: How does VWAP affect investment decisions? Day traders and short-term swing traders use VWAP as a dynamic support and resistance line. Buying above VWAP in an uptrend is generally a higher-probability trade; selling below it in a downtrend likewise. Institutions compare their execution fills against VWAP to measure trade quality.
Q: What is a real-world example of VWAP in trading? A stock opens lower and spends the first two hours below VWAP, then rallies back through it on rising volume. Many intraday traders treat that reclaim of VWAP as a bullish shift in session sentiment and use it as a long entry trigger with a stop below the VWAP level.
Q: How can investors use VWAP practically? Use it as a directional bias tool: if price is above VWAP and holding, lean long; below VWAP, lean cautious. A simple rule: do not over-interpret a single VWAP touch, price visits VWAP multiple times on most normal sessions simply because the average sits inside the day's range.
Q: How is VWAP different from a simple moving average? A simple moving average weights every bar equally and can span any number of sessions. VWAP weights each bar by its volume and resets every session at the open. VWAP reflects where most trading actually occurred in dollar terms; an SMA only reflects where price was.
Sources
- StockCharts ChartSchool. "Volume-Weighted Average Price (VWAP)." https://chartschool.stockcharts.com/table-of-contents/technical-indicators-and-overlays/technical-overlays/volume-weighted-average-price-vwap
- Corporate Finance Institute. "Volume Weighted Adjusted Price (VWAP)." https://corporatefinanceinstitute.com/resources/career-map/sell-side/capital-markets/volume-weighted-adjusted-price-vwap/
- Interactive Brokers Glossary. "Volume Weighted Average Price (VWAP)." https://www.interactivebrokers.com/campus/glossary-terms/volume-weighted-average-price-vwap/
- Charles Schwab. "How to Use Volume-Weighted Indicators in Trading." https://www.schwab.com/learn/story/how-to-use-volume-weighted-indicators-trading
Disclaimer
This article is educational content only and is not financial advice. Nothing here is a recommendation to buy, sell, or hold any security. Consult a licensed advisor before making investment decisions.
Back to your knowledge path