September 2026 is the first calendar month this site has closed from its own hourly readings, and it closed at $3.883267 per H100 SXM GPU-hour — $3.88 to the cent. That figure is the plain average of 589 hourly points, each the median of the publicly listed on-demand H100 SXM rates we had read in the 48 hours before that scrape. The month has 720 hours, so 82% of them carry a point. It was frozen at 2026-10-01 00:42 UTC and is not recomputed when later data arrives.
The four weeks under the monthly figure
The month’s weekly medians read $3.92 in the week of September 7 (20 quotes at 18 providers), $3.90 in the week of September 14 (21 at 19), $3.70 in the week of September 21 (26 at 24) and $3.56 in the week of September 28 (28 at 26). From the first of those to the last, $3.56 / $3.92 is a fall of 9.2%.
The base-100 index over the same four weeks went 100.0, 100.1, 100.4, 100.8 — a rise of 0.8%. The two columns measure different things, and the month is a larger version of what the week of September 21 showed on its own: the index links only the rates quoted in both of two consecutive weeks, so it moves when a cloud changes a price and not when the panel grows. September’s panel grew from 20 quotes at 18 clouds in the base week to 28 quotes at 26 clouds in the closing one.
The two ends of the month
The frozen review names the month’s largest single fall as EmpirioLabs’ L40S, from $1.80 to $0.80 per GPU-hour, a drop of 55.6%, in the week of September 28. Its largest rise is Sesterce’s H200, $2.09 to $2.48, up 18.7%, in the week of September 14. In the closing week the cheapest listed on-demand rates were $1.79 for an H100 SXM at Cudo Compute in no-kristiansand-1, $2.09 for an H200 at Beam and $2.69 for a B200 at ionstream; the last two are advertised from rates, which is the scope tag their rows carry.
What October’s figure stands on, and why it is not the next point
October is the first month with a fixed panel. Its 17 (provider, region) pairs, across 15 providers, were settled on the readings to September 24, 2026 and published on 2026-09-30 at 23:01 UTC, before the month began, so no choice made during the month can change who counts. Its first seven hourly points average $3.99, marked provisional.
September has no such panel: it predates the rule and is averaged over every hourly point, marked open. Two months computed over different panels are not two points of one series, and the month before September comes from a reconstructed public price catalog rather than our own reads, so no month-over-month change is stated anywhere. The rule is that such a change is stated only from two closed months of the same series.
Checking any number here
Every figure above is listed under this piece with the page it was read from and the
time of the read. The month as published is at /market/2026-09; the monthly series is
price-index-monthly.csv and October’s panel is a CSV of its own. That review page also
prints its own disagreement with itself: recomputing September from later data makes the
largest fall Sesterce’s B300 at -37.4% rather than the L40S at -55.6%, and the page
lists both with their dates instead of replacing the first. Nothing here is forecast and
nothing is a recommendation; every line is a statement about readings taken on the dates
given.