Indices as a separate book from FX scalps

[FXS London Scalper]

Plenty of FX scalpers add NAS100 or GER40 at some point, usually at the NY open or the Frankfurt cash open. The common mistake is treating index trades as just another symbol in the same daily risk budget.

Reasons to keep them apart:

- Point value and volatility are on a different scale. A routine 30-point NAS100 move can be several times the dollar risk of a normal EURUSD scalp at "the same" lot size.
- Sessions differ. Index liquidity is tied to cash hours. Spreads outside them can be wide.
- Correlation is hidden. Long NAS100 and short USDJPY at the same time can be the same risk-on trade twice.

A simple structure:

• Separate daily loss limit for indices, e.g. 40% of the FX limit while you are still learning them.
• Separate journal tag and separate stats. Mixing them hides whether either one has an edge.
• No index trade if an FX position in a correlated pair is still open.

After two or three months of separate data, it becomes obvious whether the index book adds anything or just adds variance.

If you trade both, how do you split risk between them?