Documentation

Correlation

Use the correlation matrix to understand whether positions truly diversify each other or simply move together.

What correlation means

Correlation compares how two return series move relative to each other over time.

A reading close to 1 means two assets tend to move in the same direction. A reading close to -1 means they often move in opposite directions. A reading close to 0 means their movements do not show a strong linear relationship.

Important

Correlation is not static. It can change across market regimes, especially during stress periods when many assets begin to move together.

Reading the scale

Use broad ranges instead of treating every decimal change as a meaningful decision signal.

0.80 to 1.00

Strong positive correlation

0.30 to 0.79

Moderate positive correlation

-0.29 to 0.29

Weak or no meaningful correlation

-0.79 to -0.30

Moderate negative correlation

-1.00 to -0.80

Strong negative correlation

How to use it in a portfolio

Correlation is most useful when you compare it with position sizes, sector exposure, and concentration risk.

  • Look for clusters of highly correlated positions that may behave like one trade.
  • Review correlation after rebalances, not only when opening a new position.
  • Do not assume international diversification is real if correlations remain high.

Practical rule

If two large positions stay strongly correlated, reduce the combined exposure or accept that the portfolio is less diversified than it appears.