Diversification on the ticket list is not diversification in the P&L. Audit the book as a single bet.
Common FX stacks
Long AUDUSD, long NZDUSD, and short USDJPY can collapse into one USD or risk-sentiment bet. Count exposures by driver, not by symbol count.
Index plus FX beta
Long NAS100 CFD plus short USDJPY may be double risk-on. Stress the book: what happens if equities gap down and the dollar jumps?
A simple audit
Once a day, write the one-sentence common theme of your open risk. If you cannot, you may be overfit to charts and underfit to portfolio risk.
Caps that help
Limit total risk to one theme (for example max 1% account risk to “USD short”). New tickets in the same theme must fit the remaining budget.