Why these five companies?

Microsoft, Alphabet, Amazon and Meta are the four largest AI-infrastructure capex spenders with comparable quarterly disclosure, and NVIDIA's data-center segment is the dominant supply-side line. The roster is fixed and any change would be versioned in the changelog.

Is 647.7 a market size?

No. It is an index of a gross, overlapping flow of reported figures — useful for rate-of-change, not for totals.

Within days of each big-4/NVIDIA earnings print — roughly eight times a year.

BRAIAIN Index Last updated: 2026-10-20

The BRAIAIN Buildout Index

Name: BRAIAIN Buildout Index, quarterly, 2022–2026
Creator: BRAIAIN
Published: 2026-10-20
License: https://creativecommons.org/licenses/by/4.0/

As of Q2 2026 the BRAIAIN Buildout Index stands at 647.7 (base: Q1 2022 = 100). The underlying combined flow — big-4 hyperscaler capital expenditure plus NVIDIA data-center revenue — grew from $39.4B to $255.0B per quarter over those 18 quarters, a 55.2% compound annual rate, including a dip to 97.7 in Q1 2023 before the post-ChatGPT acceleration.

Index level by calendar quarter, Q1 2022 = 100, scale 0–648. Chart drawn from the table below.

The data

quarter	msft capex musd	googl capex musd	amzn capex musd	meta capex musd	nvda dc revenue musd	combined flow musd	index q1 2022 eq 100
2022Q1	5340	9786	14951	5548	3750	39375	100.0
2022Q2	6871	6828	15724	7747	3806	40976	104.1
2022Q3	6283	7276	16378	9518	3833	43288	109.9
2022Q4	6274	7595	16592	9223	3616	43300	110.0
2023Q1	6607	6289	14207	7087	4284	38474	97.7
2023Q2	8943	6888	11455	6354	10323	43963	111.7
2023Q3	9917	8055	12479	6763	14514	51728	131.4
2023Q4	9735	11019	14588	7899	18404	61645	156.6
2024Q1	10952	12012	14925	6715	22563	67167	170.6
2024Q2	13873	13186	17620	8472	26272	79423	201.7
2024Q3	14923	13061	22620	9202	30771	90577	230.0
2024Q4	15804	14276	27834	14836	35580	108330	275.1
2025Q1	16745	17197	25019	13692	39112	111765	283.8
2025Q2	17079	22446	32183	17012	41096	129816	329.7
2025Q3	19394	23953	35095	19370	51200	149012	378.4
2025Q4	29876	27851	39522	22140	62300	181689	461.4
2026Q1	30876	35674	44203	19840	75200	205793	522.6
2026Q2	35802	44924	54208	31080	89000	255014	647.7

Download: CSV · JSON — compiled data CC BY 4.0; underlying sources keep their own terms.

Method & caveats

Index(q) = 100 × [capex(MSFT)+capex(GOOGL)+capex(AMZN)+capex(META)+DC revenue(NVDA)](q) ÷ [same sum in Q1 2022]. Component definitions follow each company's filings (see the capex page). The two component types overlap — hyperscaler chip purchases appear in both their capex and NVIDIA's revenue — so the sum is a gross, overlapping flow, not de-duplicated market spending, and the index is a measure of reported buildout intensity rather than a market total. NVIDIA fiscal quarters are mapped to the nearest calendar quarter (~1 month offset). The index was launched Oct 2026 with base Q3 2025 = 100 and re-based the same week to Q1 2022 = 100 when the back-series was completed; the changelog records this. Re-based within days of each earnings season.

Sources

Questions

Why these five companies?: Microsoft, Alphabet, Amazon and Meta are the four largest AI-infrastructure capex spenders with comparable quarterly disclosure, and NVIDIA's data-center segment is the dominant supply-side line. The roster is fixed and any change would be versioned in the changelog.
Is 647.7 a market size?: No. It is an index of a gross, overlapping flow of reported figures — useful for rate-of-change, not for totals.
When does it update?: Within days of each big-4/NVIDIA earnings print — roughly eight times a year.

Cite this

BRAIAIN. "The BRAIAIN Buildout Index." www.braiain.com/buildout-index.html, updated 2026-10-20. Original sources as listed above.

Part of BRAIAIN — the AI buildout, measured. Every figure carries its source and date; the full rules are in the methodology. Corrections: see the contact note there. © 2026 BRAIAIN, a dnilgis project.