Effort and result compares activity with achieved price change. In classical analysis, volume represents effort and price progress represents result. It is an analytical model, not a physical conservation law or proof of participant intention.
Define the measured result
Result may mean high−low range, close change, progress beyond an earlier extreme or movement across several bars. These differ; identify the measure first.
“Spread” in classical price–volume analysis often means the bar’s price range. It is not the bid–ask spread between buying and selling quotations.
Hypothetical example
A first bar has volume of 1,000 units, range 4 and close gain 3. A second has volume 2,000, range 2 and close gain 0.2. Activity doubled, while the chosen price result fell.
This invites investigation of opposing activity or lack of progress. Two bars cannot prove distribution: auctions, news, session features and other explanations remain possible.
Little activity, a large movement
At volume 500, price can travel a wide range. The movement is not automatically weak: limited opposing liquidity may allow a large change.
Compare the same instrument, duration and reasonably comparable sessions. These figures establish no universal threshold.
Volume may not be turnover
Tick volume measures updates in a particular stream. Zero may indicate unavailable data, not absent trading. Changing providers requires checking comparability.
See what candles do not show. Without comparable volume, do not claim volume confirmation.
The principle is discussed in The Illustrated Wyckoff. Use it with range context; it does not predict the next candle.