# Dollar volume

Dollar volume is the monetary value of shares traded over a period, calculated by adding each trade’s share price multiplied by its share quantity.

## What it means

Share volume counts how many shares changed hands; dollar volume expresses those trades in money. For a US stock, it is usually reported in US$ per trading day. It lets you compare trading activity in stocks with very different share prices: one million shares at US$2 represent much less traded value than one million shares at US$100.

Dollar volume describes **completed trades**, not the amount currently available to buy or sell at a quoted price. It is a measure of trading activity and a useful liquidity indicator, but it is not a direct measure of market depth or a promise that a particular order will fill without affecting the price.

## How it is calculated

For an exact total over a chosen period, use `Dollar volume = Σ (P_i × Q_i)`.

- `Σ` means add the values for all trades in the period.
- `P_i` is the price of trade `i`, in US$ per share.
- `Q_i` is the number of shares in trade `i`.

The result is in US$. Specify the period: **US$ per trading day** means a daily dollar-volume figure; an average across several days is average daily dollar volume. If trade-by-trade prices are unavailable, `closing price × daily share volume` is a rough daily proxy, not the exact traded value. A volume-weighted average price (VWAP) calculated from the same trades gives the exact relationship `Dollar volume = VWAP × total shares traded`.

For a European listing, use its trading currency for the calculation. Comparing dollar volume across currencies requires conversion into a common currency; the exchange rate and the time used for conversion should be clear.

## Worked example

Consider a **hypothetical** US stock with only two trades during the period:

1. A trade of 40,000 shares at US$25.00 contributes `40,000 × US$25.00 = US$1,000,000`.
2. A trade of 60,000 shares at US$25.50 contributes `60,000 × US$25.50 = US$1,530,000`.
3. Adding them gives `US$1,000,000 + US$1,530,000 = US$2,530,000` in dollar volume for that period.

Total share volume is 100,000 shares. VWAP is `US$2,530,000 ÷ 100,000 = US$25.30 per share`, so `US$25.30 × 100,000 = US$2,530,000` confirms the total. Multiplying share volume by the last trade price, US$25.50, would instead give US$2,550,000: a proxy that overstates the exact total by US$20,000.

## Why it matters before you trade

Dollar volume puts a proposed order in context. In the hypothetical example, an order valued at US$25,300 is 1% of the period’s US$2,530,000 traded value. That comparison is a **value-based ratio**; it is not necessarily the same as the order’s share-based participation rate, especially when prices vary.

A larger order relative to typical trading activity may be harder to execute at a quoted price. Check the period used and whether activity is typical: one unusually busy day can distort a single-day comparison. Dollar volume should be considered alongside the bid-ask spread, available market depth, volatility and the order’s execution conditions. Historical trading value cannot establish how much liquidity will be available when an order is placed.

## How PreTrAIde uses it

PreTrAIde’s pre-trade analysis enriches stocks with market-data fields that include end-of-day prices and volumes. Its quantitative layer estimates participation in daily volume, liquidity scores and tiers, bid-ask spread and market impact. Dollar volume can help a reader understand the value of trading activity, but the product facts do not specify a standalone dollar-volume calculation or say that PreTrAIde uses it as a scoring input.

For a user-built stock basket, PreTrAIde returns decision-support verdicts and reasoning before the user places any order with their own broker. Those verdicts are not trade recommendations or guarantees of execution.

## Common mistakes

- **Confusing shares with money:** 100,000 shares traded is share volume; its monetary value depends on trade prices.
- **Treating a closing-price proxy as exact:** Prices may differ across trades throughout the day.
- **Mixing periods or currencies:** A weekly figure cannot be compared directly with a daily figure, or US$ with euros without conversion.
- **Assuming traded value equals available liquidity:** Executed volume does not show how many shares can be traded now at the displayed quote.
- **Calling a ratio dollar volume:** Order value divided by daily dollar volume is a percentage; the denominator itself is a monetary amount.

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Source: https://pretraide.com/glossary/dollar-volume