See whether your symbols move as one trade or genuinely spread your risk.
Pearson correlation of daily log returns over roughly one trading year. Bars are matched by timestamp, never by position, so instruments with different sessions or holiday calendars are compared only on days both actually traded. Missing bars are dropped rather than filled - filling would invent zero returns and bias every correlation toward zero. Pairs with fewer than 30 overlapping bars are shown as “-” instead of a number.
It shows whether the instruments you hold are really separate bets. A correlation of +1 means two symbols move together, −1 means they move opposite, and 0 means no reliable relationship. A watchlist where most pairs sit above +0.7 is effectively one trade repeated several times: a single adverse move hits every position at once, so the portfolio carries far more risk than the number of tickers suggests.
TraderAI uses the Pearson correlation of daily LOG RETURNS, not raw prices. Correlating price levels of two trending assets returns nearly 1.0 for almost any pair - both went up - which carries no information. Bars are matched by TIMESTAMP, never by position in the array: two instruments can have the same number of candles yet cover different calendar days, so a bar missing on one side is dropped rather than filled, and pairs with fewer than 30 overlapping bars are shown as “-” instead of a number.
Above +0.7 (or below −0.7) is conventionally treated as strong. Between +0.3 and +0.7 the relationship is real but partial, and between −0.3 and +0.3 there is no dependable link. A negative correlation is a genuine hedge: the two positions offset each other. Note that correlation is not stable - pairs that look independent in calm markets frequently converge toward +1 during a sell-off, which is exactly when diversification is supposed to help.