# Euronext

Euronext is a European stock-exchange group operating markets in several countries where shares and other securities are listed and traded.

## What it means

Euronext names an exchange group, not a single stock, index, or trading currency. Its markets operate in multiple European countries. A share listed on Euronext Paris, for example, trades on a particular market under that market’s rules; saying only that it is a “Euronext stock” leaves out useful execution details.

For a private investor, the relevant details include the specific listing, trading currency, market hours, current bid and ask, and order conditions. A company may have securities trading on more than one venue, so its name alone may not identify the quote a broker will use. An exchange provides a venue for trading; an investor normally submits an order through a broker, not directly to the exchange.

## How it is calculated

Euronext is an exchange group, so there is no formula for calculating “Euronext.” A measurable quantity relevant to an order on one of its markets is the **quoted bid-ask spread**: `spread = ask price − bid price`. The *ask price* is the quoted price at which a seller offers shares; the *bid price* is the quoted price at which a buyer offers to purchase them. Both prices and the resulting spread are expressed in the share’s trading currency per share.

For a simple estimate, `quoted spread cost = (spread ÷ 2) × shares`. This assumes a buy at the quoted ask, an immediate valuation at the bid-ask midpoint, and enough shares available at that ask. It excludes commissions, market impact, currency conversion, and later price changes. A sell at the bid can be assessed against the same midpoint in the same way.

## Worked example

Consider a **hypothetical** share trading on Euronext Paris in euros. Suppose the displayed bid is €49.90, the ask is €50.10, and the intended order is for 100 shares.

1. Calculate the spread: €50.10 − €49.90 = **€0.20 per share**.
2. Calculate the midpoint: (€49.90 + €50.10) ÷ 2 = **€50.00 per share**.
3. If all 100 shares could be bought at the ask, the purchase amount would be 100 × €50.10 = **€5,010**.
4. The midpoint value at that moment would be 100 × €50.00 = **€5,000**. The difference is **€10**, or half the €0.20 spread multiplied by 100 shares.

The €10 is a hypothetical spread-cost estimate, not a guaranteed fill cost or a prediction of profit or loss. If only part of the order is available at €50.10, the remaining shares could fill at other prices or not fill at all.

## Why it matters before you trade

Identifying the exact Euronext market helps an investor check whether a quote corresponds to the intended security, currency, and trading session. A euro-denominated listing, for instance, can introduce currency-conversion costs or currency risk for an account measured in another currency.

The exchange name alone says little about execution cost. Spread, available liquidity, order size relative to daily volume, and market impact can differ substantially between securities on the same market. Market hours and auctions can also affect when and how an order is matched. A pre-trade check separates these order-level questions from a view about the company itself.

## How PreTrAIde uses it

PreTrAIde supports stocks on major European exchanges, including Euronext Paris. In its Pre-trade analysis, a user specifies each stock’s buy or sell side, quantity, and execution conditions in a basket before placing an order. PreTrAIde estimates factors including spread, participation in daily volume, market impact, daily volatility, and liquidity. It returns a GO, NO-GO, or MODIFY verdict with reasoning for each line and the basket.

Those verdicts are decision support, not recommendations. PreTrAIde does not receive, transmit, or execute orders; users trade through their own brokers. Its estimated spread is not a live executable quote.

## Common mistakes

- **Treating Euronext as one market or one currency.** Check the specific listing and its trading currency.
- **Confusing an exchange with an index.** An index tracks a defined set of securities; Euronext operates trading markets.
- **Assuming the displayed ask covers the entire order.** Quoted size and later fills can change the effective cost.
- **Equating the spread estimate with total cost.** Commissions, market impact, and currency conversion may add costs.

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Source: https://pretraide.com/glossary/euronext