VSA Test Bar
A test bar is a volume spread analysis (VSA) signal in which price dips into an area where supply previously appeared, on a narrow spread and noticeably low volume, and closes in the middle or upper part of its range. It is a Volume & Order Flow concept. The Library holds 1 implementation, ready to run on Vela.
Top VSA Test Bar indicator
The top custom implementation, built on the original standard VSA Test Bar formula.
1 total
Want to trade VSA Test Bar? Put the implementation below on a live chart in Vela, and Quant will help you build a strategy on it and backtest it.
What is a VSA test bar?
A test bar is a volume spread analysis (VSA) signal in which price dips into an area where supply previously appeared, on a narrow spread and noticeably low volume, and closes in the middle or upper part of its range. The logic, popularized by Tom Williams and rooted in Wyckoff's reasoning, is that strong hands who have been absorbing stock will mark price down deliberately to see whether sellers remain. If the dip attracts almost no volume, the test succeeded: supply is gone, and the path of least resistance is up. If the dip attracts heavy volume, the test failed, and more work (or lower prices) is needed.
The concept exists because absorption alone does not prove a market is ready to rise. Heavy buying at lows, visible as stopping volume or a spring-like shakeout, tells you demand appeared, but not whether sellers are finished. The test is the follow-up question, and its answer is read in the volume, not the price. That is why VSA traders insist volume on a test must be low relative to recent bars, judged against a baseline such as relative volume rather than eyeballed.
Traders care about tests because they offer a low-risk entry location: the signal itself defines the invalidation (the test bar's low), and a successful test that is then confirmed by an up bar on expanding volume is one of the classic VSA long entries. Like every single-bar read, though, it depends heavily on context; a "test" in a downtrend with no prior evidence of accumulation is usually just a pullback.
How to identify a test bar
A valid test needs prior evidence of demand; the bar itself only asks the question.
- 1Establish context: recent high-volume down bars that held, a shakeout, or other signs of absorption near a low.
- 2Watch for a bar that trades below the prior bar's low or into the earlier high-volume area during the bar.
- 3Require low volume, clearly below the recent average and well below the volume of the original supply bars.
- 4Require a narrow to moderate spread with the close in the middle or upper third of the bar's range.
- 5Wait for the response: a successful test is typically confirmed within a few bars by an up bar closing firm on rising volume. No response, or a slide below the test low, negates the read.
How traders use it
- As a long entry after accumulation evidence: enter on the confirmation bar following a successful test, with the stop below the test bar's low.
- As a supply gauge on breakouts: a low-volume test back into a broken level is read as confirmation that sellers there are exhausted, similar in spirit to classical breakout confirmation via retest.
- As a warning when it fails: a test that draws high volume tells the trader supply is still present, often preceding another leg down or more ranging.
- With discipline about context: Williams-style teaching, echoed in Wyckoff's nine buying tests, treats the test as one item of evidence within a background of strength, not a standalone buy signal.
Test bar vs neighboring concepts
Spring: A spring breaks below a defined range low to flush sellers and can print meaningful volume; a test is a quieter, later event that probes on deliberately low volume. Springs are often followed by tests.
No Demand / No Supply Bars: A no-supply bar shares the low-volume down-bar anatomy but is a passive observation anywhere on the chart. A test is that anatomy in a specific place: probing into prior supply after evidence of accumulation.
VSA Test Bar FAQ
Turn VSA Test Bar into a trading strategy.
Open the implementation from this page in Vela. Quant, our coding agent, builds the strategy with you and backtests it on real data.
Browse this familyVolume & Order Flow91 concepts mapped · 91 in the Library
- 80% Rule
- Absorption & Exhaustion
- Accumulation/Distribution Line
- Anchored VWAP
- Auction Failure
- Auction Market Theory
- Balance vs Imbalance
- Better Volume Classifications
- Bid/ask Imbalance
- Bill Williams Market Facilitation Index
- Block Trades
- Chaikin Money Flow
- Chaikin Oscillator
- Churn
- Climactic Action
- Cumulative Volume Delta
- Day-type Taxonomy
- Delta Divergence
- Delta Profile
- Demand Index
- DOM
- Ease of Movement
- Excess
- Execution Algo Footprints
- Footprint Concepts
- Force Index
- Herrick Payoff Index
- High/low-volume Nodes
- Iceberg Detection
- Initial Balance
- Intraday Intensity
- Klinger Volume Oscillator
- Manipulation Footprints
- Midpoint/half-back of Session
- Money Flow Index
- Naked POC
- Negative Volume Index
- No-demand / No-supply Bars
- OBV
- OBV Divergence
- One-timeframing
- Open Types
- Order-book Imbalance
- Periodic VWAPs
- Pocket Pivot
- Point of Control
- Poor High/poor Low
- Positive Volume Index
- Price Volume Trend
- Price Zone Oscillator
- Profile Shape Taxonomy
- PVO
- Relative Volume
- Responsive vs Initiative Activity
- Resting Liquidity / Liquidity Heatmap
- Rolling VWAP
- Rotation Factor
- Session VWAP
- Single Prints
- Smart Money Index
- Spike Rules
- Stopping Volume
- Strength/weakness Background
- Sweep Detection
- Tape Reading
- TPO Profile
- Trade Volume Index
- Twiggs Money Flow
- Unfinished Auction
- Unfinished Business
- Up/down Volume Ratio
- Value Area
- Value Migration
- Volume at Breakout
- Volume Delta
- Volume Divergence
- Volume Dry-up
- Volume Flow Indicator
- Volume Oscillator
- Volume Price Trend
- Volume Profile
- Volume Spike
- Volume Spread Analysis
- Volume Zone Oscillator
- VPCI
- VSA Test Bar
- VWAP Bands
- VWAP Mean-reversion vs Trend Regimes
- VWAP Pinch
- Weis Wave Volume
- Williams A/D
