Choosing your first index
Learning objectives
Apply five criteria to select an index suited to your account, hours and understanding
Explain why US indices are largely a single trade rather than separate ones
Match an index's cash hours to the time you can actually trade
Which index should you trade?
Most retail traders end up on a US index without deciding to. It's often the right answer, but it's worth arriving at deliberately.
Here are 5 criteria to help you choose.
1. Point value against your account. As Indices CFD trading 101 showed, contract specifications vary enormously between brokers and indices. An index quoted at $10 per point needs ten times the account of one quoted at $1 for the same stop distance. Check the specification before anything else.
2. Typical daily range. A broad index covering three quarters of a percent behaves very differently from a technology index covering twice that. Both are tradeable. Only one suits a small account with a wide stop.
3. Cash hours against your hours. Covered below, and it's the criterion that eliminates most options fastest.
4. Whether you understand what moves it. What moves index markets showed that each benchmark has its own drivers. If you can't say in a sentence what would move your chosen index, you have no way to tell an ordinary move from a significant one.
5. Correlation with everything else you hold. The one people miss, and it's worse here than in forex.
The default
The S&P 500.
It's the most liquid index instrument available, which means the tightest spreads and the least slippage. It's the most analysed market in the world, so you can always find out why it moved. Its daily range is moderate by index standards. And its drivers, being Fed policy and US growth, are the same ones the Fundamental Analysis course already taught you.
The caveat from What is an index: S&P 500, FTSE 100, Nasdaq stands: it's more concentrated in megacap technology than "500 companies" implies. Know that, and it's still the sensible starting point.
Alternatives worth considering
Nasdaq 100 if you want more movement and understand you're taking a more rate-sensitive, more concentrated position. It moves further than the S&P on the same news, which is opportunity and risk in equal measure.
FTSE 100 if you're in a European timezone and want an index whose cash hours align with your working day. Bear in mind it's a commodities and sterling trade more than a UK economy trade.
DAX 40 for European hours with an industrial and export character.
Nikkei 225 or Hang Seng if you're in Asia and want cash hours in your own working day. The Nikkei in particular is heavily influenced by the yen, so a position there is partly a currency view.
Hours are the real constraint
This decides more than anything else on the list, and the answer differs by where you are.
A US index's cash session runs roughly 14:30 to 21:00 UK time. From the Gulf that's late afternoon into the night. From Southeast or East Asia it's the evening and overnight.
A European index's cash session runs roughly 08:00 to 16:30 UK. From the Gulf that's midday to early evening, which is genuinely workable. From Asia it's afternoon into evening.
An Asian index's cash session falls in the Asian working day, which suits traders there and nobody else.
You can trade any index outside its cash hours, because the CFD is priced from futures as Index trading hours: cash vs futures pricing explained. But you'll be trading at wider spreads in a thinner market, with a stop that's more vulnerable, for no compensating benefit.
Pick an index whose cash session overlaps hours you can genuinely give. Trading styles: scalping, day, swing and position made session availability one of the three constraints that should determine your approach, and here it determines your instrument too.
The correlation trap
In forex, three positions sharing a currency are substantially one bet. In indices it's more extreme.
The S&P 500, Nasdaq 100 and Dow all move together the great majority of the time. They share constituents, they share drivers, and they respond to the same central bank. Holding long positions in two of them is not diversification, it's one position at double size, and Managing leverage as a beginner explained why your effective leverage is the sum.
It extends beyond indices. Global equity markets are correlated, particularly during stress, so a long DAX position alongside a long S&P position is less independent than it looks. And an index position alongside a long crypto position may be closer than you'd expect, which Crypto correlations with traditional markets covers.
The practical rule: one index at a time, unless you can state specifically why two are different trades. "One is American and one is German" is not a sufficient answer during a global risk-off move.
A process
- Check the point value on your platform for two or three candidates.
- Note which cash sessions overlap hours you can genuinely trade most days.
- From what remains, pick the most liquid.
- Trade only that for a defined block of trades, matching the review cadence in Building your own risk rules.
- Before adding a second, state what would make it move differently from the first. If you can't, don't add it.
Key takeaways
Check the point value first. Contract specifications vary enough between brokers and indices to change your position size by a factor of ten
The S&P 500 is the sensible default: most liquid, most analysed, moderate range, and driven by forces you've already studied
Cash session hours are the constraint that eliminates options fastest. Trading an index outside its session means wider spreads and a more vulnerable stop
US indices are largely one trade. Holding two is a single position at double size, not diversification