Underground, submarine and superconducting cables: Correlation
Prices it moves with, and why
Cable prices are set mostly by copper or aluminium conductor plus polymer insulation, with makers passing metal costs through by formula. Submarine and high-voltage cables also depend on scarce factory and cable-laying vessel capacity.
Proxy US PPI: other communication and energy wire index (BLS base period =100) · monthly, Jan 2006 to Sep 2026There is no free public price for underground, submarine and superconducting cables itself, so this tab uses the closest public series as a stand-in. Read the numbers as an indication, not as the price of this exact item.
What its price moves with
Selected linkUnderground, submarine and superconducting cables and Copper
Monthly changes 0.50 moderate correlation 12-month changes 0.71 strong correlation Last 5 years 0.26 monthly changes Lead or lag +1 mo Copper tends to lead by 1 month (r 0.57) Price function, Jan 2006 to Sep 2026 Underground, submarine and superconducting cables ≈ 0.423 × (Copper)0.70 R² 0.58 On this fit, a 10% higher copper price goes with a 6.9% higher underground, submarine and superconducting cables price over the long run. Units: index (BLS base period =100) and $/mt.Chart: Underground, submarine and superconducting cables and Copper prices rebased to 100 at Jan 2006, log scale
Both prices rebased to 100 at Jan 2006, on a log scale so equal percentage moves look the same size.Chart: Underground, submarine and superconducting cables price against Copper price, monthly, log scales, with fitted line
Each dot is one month; paler dots are older (2006), darker dots recent (2026); the ringed dot is the latest month. The dashed line is the fitted price function. Both axes are logarithmic.Copper is the largest material cost in most power cables, and makers adjust prices for metal. This shows clearly in the data: monthly changes correlate at 0.50 and yearly changes at 0.71, with copper leading by about one month.
moderate co-movement month to month · 249 months Show chartsAluminium replaces copper in many overhead and large underground cables because it is lighter and cheaper for the same conductance. The cable index follows it at 0.32 for monthly moves and 0.75 for yearly moves, with aluminium leading by about a month.
weak co-movement month to month · 249 months Show chartsCross-linked polyethylene is the standard insulation for power cables. The plastics proxy correlates at 0.27 for monthly moves and 0.68 for yearly moves, reflecting both resin costs and the shared influence of oil on materials.
weak co-movement month to month · 249 months Show chartsSubmarine and some high-voltage cables use lead sheaths to keep water out. Lead is a minor share of total cost, so the link is loose, with monthly moves correlating at 0.22 and yearly moves at 0.49.
weak co-movement month to month · 249 months Show chartsHVDC projects buy cable and converter stations together, so the transformer proxy and the cable index rise in the same grid investment cycles. Monthly moves correlate at 0.34 and yearly moves at 0.72.
weak co-movement month to month · 247 months Show chartsOffshore wind farms need array and export cables, and this demand has filled order books at the few submarine cable plants. The turbine proxy shows no link to the cable index, with monthly moves at 0.00, because turbines and cables are priced separately.
little or none co-movement month to month · 184 months Show chartsHow to read these numbers
Correlation of monthly changes (the number in the coloured pill) compares how much each price moved, month by month, since 2006 or the first month both series exist. It runs from −1 to +1: near +1 the two usually rise and fall in the same months, near 0 there is no link, and a negative number means they tend to move in opposite directions. Above 0.7 is strong, 0.4 to 0.7 moderate, 0.2 to 0.4 weak.
12-month changes compare year-on-year moves, which shows whether two prices share the same cycles even when the month-to-month noise differs.
Price function is a straight-line fit of the two prices on logarithmic scales: price ≈ k × (partner price)β. β is how much this price moves, in per cent, for a 1% move in the partner over the whole period, and R² is the share of the variation the fit explains. Two prices that both drift up with inflation can fit well without any real link, so read it together with the monthly correlation.
Lead or lag checks whether the monthly correlation is clearly higher when one price is shifted by 1 to 6 months.
Correlation is not cause. The reasons on each card explain the economic link; the numbers show how strongly it has shown up in prices. Proxy series are US producer price indexes or related prices and can blur the real link.
Data: World Bank Commodity Price Data (Pink Sheet), October 2026; US Bureau of Labor Statistics producer price indexes, IMF primary commodity prices and US EIA prices via FRED, Federal Reserve Bank of St. Louis, retrieved November 2026. Calculations by this site.