Nasdaq 100 and S&P 500 from a Euro Account: Hours and Currency Risk

The Nasdaq 100 and the S&P 500 are the most watched indices in the world, and many French traders study them alongside the CAC 40. Two things change when your account is in euros: the hours, and a second risk that many beginners never see, the exchange rate.

The two US indices in brief

	S&P 500	Nasdaq 100
Members	About 500 large US companies	100 large non-financial companies listed on Nasdaq
Weighting	Free-float market cap	Modified market cap
Character	Broad US market	Heavy in technology and communication
Quoted in	US dollars	US dollars

Because a handful of very large technology companies dominate both, they often move together, with the Nasdaq 100 usually moving more in percent.

Hours in Paris time

The regular New York session runs from 09:30 to 16:00 local time, which is 15:30 to 22:00 Paris time most of the year, and 14:30 to 21:00 during the few weeks when US and European clock changes are out of step (March and late October to early November). Instruments with extended hours trade outside that window with thinner liquidity. The market sessions tool shows the current times, and European index hours in Paris time covers the overlap with Paris.

The hidden second risk: EUR/USD

A US index point is usually worth a fixed amount in dollars. Your profit or loss is therefore in dollars and converted back into euros. If EUR/USD moves while you hold the position, your result in euros changes even if the index has not moved.

A worked example, with a rate chosen only for illustration:

Item	Value
Risk budget	€100
Rate used for the example	1 EUR = 1.10 USD
Risk in dollars	€100 × 1.10 = $110
Stop	50 points
Size	$110 ÷ 50 = $2.20 per point

Illustrative calculation, not an expectation of results. Never use a remembered rate: take the current EUR/USD quote from your provider at the moment you size the trade. The pip value calculator and the lot size calculator help you check the conversion.

How currency changes a held position

• For an intraday trade the currency effect is usually small next to the index move.
• For a position held for weeks, a 3–5% move in EUR/USD can add to or subtract from the result.
• Some instruments are quoted in euros on a US index; check whether they hedge the currency and what that costs.

Planning a US-session trade from France

1. Decide your window: the first hour after 15:30 is often the most active.
2. Note US data at 14:30 and Federal Reserve days (ECB decisions and European indices explains the European side).
3. Convert the risk to dollars at the current rate, size from the stop, round down (sizing a position in index points).
4. Decide whether you hold past 22:00: the next morning's opening gap can be large.

Summary

US indices trade from 15:30 to 22:00 Paris time most of the year, are quoted in dollars and carry a currency risk for a euro account. Convert, size, and plan the late session. Trading involves risk, and most retail traders lose money.