Market constellation

Every star is an instrument. Its size, and how close it sits to you, is its surprise: the 24-hour move divided by its own 20-day volatility, in standard deviations. The surprise is the one figure that compares a currency with a coin with a stock. A star near the front is having an unusual session for that instrument, whatever its asset class. Its colour is the direction of the move, and every label also carries ▲ or ▼ and a signed number. A star drawn dashed has no measured move, which means unknown, not flat. One limit applies to every surprise reading: the numerator is a trailing 24 hours while the denominator is close-to-close over whole days, so mid-session it reads slightly tame.

Every link is a correlation of daily returns over about the last 60 trading days, measured only on days both instruments traded. These are the same numbers the correlations page prints. A solid link means the two have moved together; a dashed one means they have moved in opposite directions. Each instrument keeps its three strongest relationships above 0.5, plus any pair above 0.8. An instrument with nothing that strong is tethered by its single strongest relationship, drawn faint. The clusters form on their own, from the positive links alone, and each is named after the groups most of its members belong to.

The replay steps back through the last two months a day at a time. It draws each pair's last 20 days against the 60 before them, and calls out the moment a relationship breaks. A break uses the same test the correlations page uses: a pair that ran above 0.6 and has moved at least 0.4 away from it. The replay also calls out two clusters merging or one splitting, and any instrument having a day beyond 2.5 of its own standard deviations.

A correlation describes what the last few months did. It is not a forecast and not a hedge ratio, and two instruments moving together does not mean either one drives the other.