NAS100 and US30 lot size: how to size index trades in MT4 and MT5
With forex, one lot is 100,000 units at almost every broker. With indices, there's no such standard. One broker's NAS100 lot is worth $1 a point, another's is $10, and a third's is $20. Size an index trade the way you'd size EURUSD and you can risk ten or twenty times what you meant to.
Why index lots differ
Index CFDs are built by each broker. They choose a contract size, which sets how much one point is worth on 1.00 lot. Prop firms do the same on their own servers. So “1 lot of NAS100” means nothing until you know whose NAS100 it is.
Check it in MetaTrader in 30 seconds
- Open Market Watch (Ctrl+M) and find the index (NAS100, USTEC, US100, US30, GER40 or similar).
- Right-click it and choose Specification.
- Note the contract size, tick size and tick value.
For example, a tick size of 0.01 with a tick value of $0.01 means $1 per point per lot. A tick size of 0.1 with a tick value of $1 means $10 per point. If in doubt, open a 0.01 lot trade on a demo account and watch what one point does to the profit.
The formula
Worked example: US30
At $1 per point: 80 points = $80 = £59.70 per lot → £50 ÷ £59.70 = 0.84 → 0.83 lots (risk £49.55)
At $10 per point: 80 points = $800 = £597.01 per lot → 0.084 → 0.08 lots (risk £47.76)
Worked example: GER40 (paid in euros)
GER40 is priced in euros, so convert from euros, not dollars.
40 points = €40 = £34.63 per lot → £50 ÷ £34.63 = 1.44 → 1.44 lots (risk £49.86)
Margin on indices
UK retail traders can use up to 20:1 on major indices, so the margin is 5% of the position's value. With NAS100 at an illustrative 29,000 and a contract of $1 per point, one lot controls $29,000 and needs about $1,450 of margin. At $10 per point, the same lot needs $14,500. As always, margin isn't your risk: your stop and lot size are.
Setting sensible stops on indices
- Use the ATR. Index point moves have grown with the index level. A stop that was sensible years ago may now be inside normal noise. Check the ATR on your timeframe.
- Respect the US open. NAS100 and US30 often move hardest after the cash open at 14:30 UK (13:30 in the clock-change weeks). See New York session times in UK time.
- Watch the spread out of hours. Spreads usually widen when the US market is closed, which can trigger stops that looked safe.
Compare your index trades with your forex and gold
The Trader's Ledger logs every market in R, so you can see whether indices actually pay you better than forex or gold, by setup and session. £19 once, with a free 49-page trading course.
Get The Trader's LedgerTTL Indices Hybrid Pro finds and grades liquidity sweep setups on NAS100, US30, US500 and GER40, and reads your broker's own tick value, so the lot size it shows is right for your account. For the general method, see how to calculate lot size.
Frequently asked questions
How much is 1 lot of NAS100 worth?
It depends on your broker. $1, $10 and $20 per point per lot are all common. Check the contract size, tick size and tick value under Specification in MetaTrader.
What is a point on NAS100 or US30?
A move of 1.0 in the index price, for example from 29,000.0 to 29,001.0.
Why is my index lot size so different from a friend's?
Because your brokers almost certainly use different contract sizes. Compare risk in money, not in lots.
How much margin do I need for NAS100?
At 20:1 (the UK retail limit for major indices), 5% of the position's value. With NAS100 at 29,000 and $1 per point, that's about $1,450 per lot.
Educational content only, not financial advice. Trading carries a high level of risk and you can lose more than you expect. Examples use illustrative prices.