1992issue C041-2
Building intermarket context with linear correlation
Treat the signed correlation-coefficient as a construction gauge, not a story. Before a single position sits inside a two-market or spread frame, confirm that the scatter is straight, size the context by how close the intermarket-pair sits to plus or minus one, and refuse to promote a very small observation-count into a weeks-to-months regime label.
- The archive presents the correlation-coefficient as a bounded index of how tightly two series move together on a straight-line basis, from perfect inverse alignment through no linear alignment to perfect positive alignment.
- Editorial reading: apply the linear-restriction first and confirm that a straight line, not a curve, describes the intermarket-pair before a position is placed inside a two-market or spread frame.
- A large reading is association-not-causation: it describes co-movement and is not proof that one series makes the other large.
- Editorial reading: the worked pair uses only 10 paired closes and is flagged as a very small observation-count, too thin to promote into a weeks-to-months regime label.
What the coefficient measures
Correlation analysis is presented as a measure of the degree of relationship between two variables. The correlation-coefficient is a bounded index of how tightly two series move together on a straight-line basis. It spans perfect inverse alignment at minus one, no linear alignment at zero, and perfect positive alignment at plus one.
Computation of the coefficient is defined from the observation-count, the two series, their means, and the summed products and squares of those series.
The linear-restriction comes first
The coefficient is restricted to relationships that can be treated as linear rather than curved. The linear-restriction is the rule that the coefficient is only a fair construction input when a straight line, not a curve, describes the pair.
An intermarket-pair is two closing-price series chosen so one market can be read against another when assembling spread or portfolio context. If the scatter is curved, the signed reading is not a fair gauge for that frame.
Association is not causation
A large positive coefficient is not treated as proof that one variable causes the other to be large. Association-not-causation is the limit that a large reading describes co-movement and does not establish that one series makes the other large.
Do not promote a tiny paired sample
A worked intermarket-pair uses bond-futures closes against a commodity-index close with an observation-count of 10, flagged as very small. Observation-count is the number of paired prints used to compute the coefficient; a very small count weakens any intermarket frame built from it.
Editorial reading: refuse to promote that tiny paired sample into a weeks-to-months regime label. Size the context by how close the pair sits to plus or minus one, then stop short of treating a 10-print reading as a durable regime.
Bond futures and CRB closes behind r = -0.83

The sidebar fixes n at 10 because of space and applies the linear-r formula only. The published r is association, not cause and effect.
All readings on this track · 37 readings
- 1988Constructing a lead-aware correlation coefficient
- 1989A precious-metal price as a changing intermarket equation
- 1990Two clocks for copper: a factor regime, a regression baseline, and leftover moving-average timing
- 1990Earnings yield, rate correlation and regression for equity value
- 1991Name the window, then combine leaders
- 1991Constructing a two-market linear correlation check
- 1991Constructing a commodity-bond correlation regime filter
- 1992Building intermarket context with linear correlation
- 1993Inverse-scale overlays as a gold-equity regime filter
- 1994Constructing seasonal slots from windows, analog years, and implied volatility
- 1995Pin one reference close and roll companion correlations as an overlay
- 1995Rolling correlation windows for shifting intermarket regimes
- 1998Gold as a cross-market regime barometer
- 1999The gold-bond inverse is a regime, not a cause
- 1999A nested lag test of gold leading bond yields
- 1999Constructing spreads from stock and intermarket correlation
- 2000Evaluating headline versus food-and-energy-excluded CPI as bond-yield context
- 2005A late EUR/USD fifth wave tested by the Bund-Treasury gap
- 2006Intermarket dislocation as context for short-horizon momentum
- 2008Map ordinary 12-month outcomes before stacking valuation, rates, and seasonality
- 2008A clean-energy theme inside the oil-and-energy regime
- 2014Quantitative-easing overlays as fragile belief regimes
- 2015Three intermarket checks from the late-2014 crude decline
- 2015Basket construction via rank, correlation, and locked rules
- 2015Construct a CAD-oil pair from percent-of-range Bollinger maps
- 2015CAD/USD and crude: first the correlation, then the band gap
- 2017Correlation regime versus moving-average crossover for S&P 500 exposure
- 2017Updating intermarket systems after correlation shifts
- 2017Constructing a correlation-divergence regime filter for yen and Nikkei context
- 2018Clustered negative troughs in an energy-index pairwise correlation
- 2018Filter pairwise-correlation before reading an intermarket regime
- 2018Moving-average supports in the March 2018 correlation shock
- 2020Bond spreads as an equity regime lens
- 2020Crash-protection folklore as a correlation regime question
- 2020Constructing a bounded correlation-trend-filter
- 2020Constructing a correlation-to-line trend filter
- 2020Bitcoin correlation regimes across equities and gold