cu-index

Chain-linked geometric price index for GPU compute over listed rate-card prices, normalized to the Compute Unit. It replaced an index prototype that averaged whatever listings reported that day: on February 17 providers went from 4 to 27 and the old index printed −32% while the mean price rose. The new index chains that day at −2.3%.

Each listing contributes the ratio of its price today to its price yesterday, matched on the same provider, GPU, instance, region and price type. Relatives are combined by geometric mean and chained from 100 on February 18. The CU score cancels in the ratio, so revising the unit never rewrites history. A day is graded ok when at least 90% of the baseline providers report; thin and gap days carry flat until the next ok day.

54M+ ticks, 28 providers at peak and 15 reporting today, 42 GPUs, 3,116 listings, January 14 to September 10, 2026.