How it is calculated
For each market we take the percentage change from one daily close to the next. For every pair of markets, the Pearson correlation of those daily changes over the chosen window gives a number from −1 to +1. Only completed daily candles are used; today’s candle joins tomorrow.
Daily changes are used instead of raw prices on purpose. Two markets that both trended up for months look perfectly correlated on prices even if their day-to-day moves had nothing in common.
Indices, oil and bitcoin trade on slightly different days and hours from forex, so their numbers use the days both markets have data for. A dot means there were not enough shared days yet. To size positions on correlated pairs together, the lot size calculator and the margin calculator help keep total risk in check.
Past data, not a forecast. Not investment advice.
FAQ
What does a correlation of +0.8 mean?
On most days the two markets moved the same way, and by similar relative amounts. At −0.8 they mostly moved in opposite directions. Near 0 there was no steady link over that period.
Why should I care if I trade one EA per pair?
Two EAs on EURUSD and GBPUSD that both buy are close to one bigger bet on the dollar. If the pairs are strongly correlated, a bad day hits both at once, so the combined drawdown is larger than either backtest shows.
Why do 20-day and 60-day numbers differ?
Correlation changes with the news cycle. The 20-day view reacts to recent events; the 60-day view is steadier. When the two disagree, the link between those markets is shifting.
Does correlation tell me where price will go?
No. It describes how two markets moved together in the past, not which way either one will move next.