Will Ramp AI Index OpenAI model adoption rate for September 2026 be above 40.5%?

- [2026-09-09] Ramp published its "September 2026 Ramp AI Index" report, which despite the September title actually covers **August** month data: "43.8% of businesses in Ramp's base transacted with Anthropic last month (up 0.34 percentage points month over month), versus 39.8% for OpenAI (up 0.09 points)" — source: https://fourweekmba.com/ai-ramp-ai-index-september-2026-anthropic-openai-spend/ - [2026-09-09] Ramp's own page confirms: "OpenAI underperformed overall AI adoption, rising only 0.09 percentage points to 39.8% of businesses." That report's data-month is August 2026, not September. https://ramp.com/data/ai-index-sept-2026 - [2026-09-09] Overall adoption momentum is decelerating: "In general, new AI adoption continues to grow but is decelerating." https://ramp.com/data/ai-index-sept-2026 - [2026-08-12] The prior (August-titled) report, covering July data, showed "OpenAI underperformed overall AI adoption, rising only 0.23 percentage points to 39.7% of businesses" — the third consecutive month of sub-0.3pp OpenAI gains. https://ramp.com/data/ai-index-august-2026 - [2026-07-15] The July-titled report (June data) showed OpenAI at 39.5%, essentially flat: "OpenAI was essentially flat, edging down 0.1 percentage points to 39.5% of businesses. Anthropic rose 1.4 percentage points to 42.4%, remaining the leader in business adoption." https://ramp.com/data/ai-index-july-2026 - [2026-09-09/2026-09-23] Coverage of the September-titled (August-data) release notes a broader spend slowdown, not adoption-rate acceleration: "The median monthly AI spend per employee among the top 1% of companies decreased by 9.7%, from $7,976 to $7,205. The effective price per million tokens fell 41% from its March 2026 peak of $1.15 to $0.68. Lower-cost standard models are driving usage, while frontier models (Opus, Fable, Sol) account for 45% of token share." https://www.kucoin.com/news/flash/ramp-report-anthropic-holds-43-8-of-u-s-enterprise-ai-paid-share-in-august - [2026-09-16] Secondary analysis of the same release confirms frontier-model share pulled back "frontier models…had fallen to 45% of the tokens businesses were purchasing on Ramp's platform, down from a peak of 53% in August" (note: this "August" peak reference is itself the prior report's July data), consistent with buyers shifting toward cheaper standard models like GPT-5.6 Terra rather than expanding overall frontier/OpenAI-branded spend. https://fourweekmba.com/ai-ramp-ai-index-enterprise-frontier-pacing-demand-side/ - [2026-09-09] The report explicitly frames the trend as a continuing "Cracks in the AI Thesis" narrative, i.e., Ramp's own economist sees deceleration, not reacceleration, in frontier-model (including OpenAI) adoption: "Last month, I wrote a post called Cracks in the AI Thesis, in which I presented my view that rising adoption of cheaper models and mediocre adoption of Fable 5, posed a threat to the model companies, which rely on rising business spend on frontier models. This post is an update with my latest thinking." https://ramp.com/data/ai-index-sept-2026 - [2026-09-24 (as of today)] No Ramp report covering actual September 2026 data has yet been published; based on the monthly cadence (publications on the 9th–15th of the following month), the report with true September figures is expected in mid-October 2026, likely landing before the market's October 17 close. BOTTOM LINE: The most recent confirmed OpenAI adoption-rate figure (August 2026 data, published Sept 9) is 39.8%, following three straight months of sub-0.25-percentage-point monthly gains (39.5%→39.7%→39.8%) amid an explicitly decelerating adoption trend and a documented shift toward cheaper/standard models over frontier spend. For September's true figure (to be released in October, before market close) to exceed 40.5% would require a jump roughly 3-7x larger than any recent monthly gain, which is inconsistent with the current deceleration trend Ramp itself is highlighting. NOT FOUND: No official Ramp report with actual September 2026 data (expected mid-October) is available yet; no leaked or preliminary September adoption-rate figures for OpenAI were found in current sources.

- [2026-09-09] Ramp's own September 2026 Ramp AI Index letter (covering August 2026 spend data) reported that OpenAI underperformed overall AI adoption, rising only 0.09 percentage points to 39.8% of businesses , while 43.8% of U.S. businesses paid for subscriptions or tokens from Anthropic, up 0.34 percentage points month over month . Source: https://ramp.com/data/ai-index-sept-2026 - [2026-08-12] The prior month's letter (July 2026 data) showed OpenAI underperformed overall AI adoption, rising only 0.23 percentage points to 39.7% of businesses , indicating a similarly small monthly gain. Source: https://ramp.com/data/ai-index-august-2026 - [2026-07-15] The June 2026 data release showed OpenAI was essentially flat, edging down 0.1 percentage points to 39.5% of businesses, while Anthropic rose 1.4 percentage points to 42.4%, remaining the leader in business adoption . Source: https://ramp.com/data/ai-index-july-2026 - [2026-06-26] Two months earlier, OpenAI's adoption had actually fallen sharply: the May 2026 letter (April data) reported OpenAI adoption fell 2.9% to 32.3%, while overall AI adoption rose 0.2 percentage points to 50.6% , and for the first time, Anthropic passed OpenAI in business adoption, with Anthropic rising 3.8% in April to 34.4% . Source: https://ramp.com/data/ai-index-may-2026 - [2026-06-26] The April 2026 letter (March data) had shown OpenAI at 35.2%, with the gap between OpenAI (35.2%) and Anthropic just 4.6 points, down from 11 points in February, with the note that at that pace, Anthropic would overtake OpenAI within the next two months — a prediction that materialized the following month. Source: https://ramp.com/data/april-2026-ai-index - [2026-07-06] Going back further, the March 2026 letter (Feb. data) noted OpenAI's 1.5% decline was the largest in any single month for any AI model company since we started tracking business AI adoption , underscoring that OpenAI's index has been volatile over the past year rather than steadily rising. Source: https://ramp.com/data/ai-index-march-2026 - [2026-09-10] A third-party summary of the September letter confirms the raw figures: Ramp's September 2026 AI Index, published September 9 and built entirely from Ramp's own corporate-card and bill-pay transaction data, puts Anthropic ahead of OpenAI: 43.8% of businesses transacted with Anthropic last month (up 0.34 percentage points), versus 39.8% for OpenAI (up 0.09 points) . Source: https://fourweekmba.com/ai-ramp-ai-index-september-2026-anthropic-openai-spend/ - [2026-09-10] The same analysis frames the pattern as one of deceleration and cost-optimization rather than share gains for OpenAI: Ramp's September 2026 AI Index...shows adoption still widening while spend-per-seat softens and buyers route away from frontier models . Source: https://fourweekmba.com/ai-ramp-ai-index-september-2026-anthropic-openai-spend/ - [2026-09-10] A commentary piece on the same release observed the slowdown explicitly: The Ramp Index issue of September 9th, 2026 was particularly good...some of AI's momentum might be slowing down as well . Source: https://www.ai-supremacy.com/p/ai-insights-is-ai-adoption-slowing-down-ai-risk-debate - [2026-09-03] A secondary aggregator (Ramp vendor page) separately reports OpenAI's share within the "Foundational LLMs" category, noting OpenAI ranks #2 within the Foundational LLMs category, down 1 position month-over-month, with 78% of organizations who have a vendor in the category using OpenAI as of August 2026, down 17 percentage points from last year — a different metric (category share, not overall business adoption rate) that should not be confused with the Ramp AI Index headline number the market references. BOTTOM LINE: Over the last three reported months (June, July, August 2026 data), OpenAI's Ramp AI Index adoption rate has essentially plateaued at 39.5%→39.7%→39.8%, with monthly gains shrinking to just 0.09 percentage points in the latest release; reaching "above 40.5%" for September would require roughly a 0.7-point jump, far larger than any of the last three months' moves (though such jumps did occur earlier in 2026 during a volatile rebound period, that pattern has not recurred recently). NOT FOUND: No official Ramp AI Index release covering September 2026 data itself (it would typically publish in early-to-mid October 2026, likely before the October 17 market close, but was not yet available as of this research); no Kalshi-specific historical resolution data or betting-market odds specifically for this Ramp AI Index contract were found.

**Strongest YES case: GPT-6 Astra's launch has visibly reversed OpenAI's momentum within September, which — if it converts from spend-share into the broader "% of businesses transacting" adoption metric before the October release — is the single most plausible path to a >40.5% September OpenAI adoption figure.** - [2026-09-03] Astra rolled out to users across OpenAI's ChatGPT Plus, Pro, Business, Enterprise plans, as well as through the OpenAI API and Amazon Web Services in "the coming days." This is a full-stack enterprise release timed at the very start of the September measurement window, unlike prior incremental updates. Source: https://www.cnbc.com/2026/09/03/open-ai-astra-gpt-6-cyber.html - [2026-09-15] Ramp's own lead economist posted (via X, cited by wccftech) that Astra accounts for roughly 13% of enterprise AI spend tracked by Ramp, compared to 8% for Fable — a reversal that comes just months after Fable's own launch was supposed to cement Anthropic's position at the frontier. Source: https://officechai.com/ai/enterprises-are-spending-more-on-openais-astra-than-anthropics-fable-says-ramp-data/ - [2026-09-15] The same Ramp chart shows the speed of the shift: Fable's share climbed steadily from July onward, spiking to nearly 10% by early September before sliding back to 8%. Astra, which sat at zero for the entire summer, shot almost vertically past Fable within the space of about two weeks once it launched in September, and shows no sign of slowing down. Source: https://officechai.com/ai/enterprises-are-spending-more-on-openais-astra-than-anthropics-fable-says-ramp-data/ - [2026-09-15] Independent corroboration from a different platform: the flip isn't confined to enterprise card spend — it also showed up in OpenRouter's own wallet-share data, where OpenAI models pulled ahead of Anthropic's for the first time in two and a half years in the same stretch of September. Source: https://officechai.com/ai/enterprises-are-spending-more-on-openais-astra-than-anthropics-fable-says-ramp-data/ - [2026-09-23] Ramp's newest weekly Token Spend leaderboard (week of Sept 14–20) shows OpenAI's newly launched GPT-6 Astra sits at the top... OpenAI models account for the largest single share at the very top, driven by Astra's rapid uptake. Astra alone captured 18.9% of the $27.9M sample token spend, with three of the top nine models being OpenAI's. Source: https://officechai.com/ai/these-are-the-ai-models-with-the-most-customer-spend-as-per-ramp/ - [2026-09-23] The same report notes overall paid AI adoption in Ramp's base has kept climbing to a new high: Ramp's wider AI Index continues to show paid AI adoption at 56.1% among the more than 70,000 U.S. businesses on its platform—well above Census Bureau estimates. A rising overall-adoption denominator gives OpenAI more room to add share even without stealing existing Anthropic users. Source: https://officechai.com/ai/these-are-the-ai-models-with-the-most-customer-spend-as-per-ramp/ - [2026-09-15] Ramp's economist explicitly frames this as a strategic failure for Anthropic that benefits OpenAI: Anthropic took a big risk in its recent call to pace the frontier. If Anthropic's pacing strategy continues to lag, new business AI budget allocated in September could disproportionately flow to OpenAI's Astra rather than to Claude, pushing the "% of businesses transacting with OpenAI" metric up faster than the prior three months' ~0.1–0.25pp pace. Source: https://wccftech.com/gpt-6-astra-helped-openai-attract-more-enterprise-dollars-than-anthropic-last-week-flipping-a-paradigm-that-held-for-2-5-years-as-sam-altman-teases-huge-upcoming-product-releases/ - [2026-09-15] Anecdotal internal-demand signal reported in the same period: an OpenAI-side source described the launch's traction as unusually strong, saying " Demand for Astra is really unprecedented. We're pulling all the levers possible to sustain the demand, but I've not seen anything like it until now and we went through very steep growth before. " This suggests capacity-constrained but rapidly broadening usage, consistent with new-business signups rather than just existing-customer upsell. Source: https://www.ai-supremacy.com/p/ai-insights-is-ai-adoption-slowing-down-ai-risk-debate - [2026-09-15] Sam Altman publicly teased an accelerating release cadence right as Astra's spend-share surge was reported — " big 🚢 this week and then for devday 🚢🚢🚢🚢🚢🚢 " — implying further OpenAI product launches inside the September measurement window that could compound adoption gains beyond Astra alone. Source: https://wccftech.com/gpt-6-astra-helped-openai-attract-more-enterprise-dollars-than-anthropic-last-week-flipping-a-paradigm-that-held-for-2-5-years-as-sam-altman-teases-huge-upcoming-product-releases/ **Mechanism/prerequisites for YES:** The Ramp AI Index headline "adoption rate" is a binary measure of whether a business had *any* paid transaction with a vendor in the month — not spend share. For September's figure to jump from 39.8% to above 40.5% (a ~0.7pp move, 3–8x the recent monthly pace), Astra's token-spend surge would need to translate into a wave of *new* first-time OpenAI corporate-card/bill-pay transactions (new logos or previously-non-paying seats activating billing), not just existing OpenAI customers spending more on a new model. The spend-share data (Astra jumping from 0% to ~13–19% of tracked token dollars within two weeks) is consistent with, but does not directly confirm, such a broadening of the payer base. BOTTOM LINE: The strongest YES driver is concrete and dated: GPT-6 Astra's September 3 launch produced a documented, rapid reversal in enterprise spend-share (0%→13-19% within two weeks, confirmed independently by Ramp and OpenRouter data as of Sept 15 and Sept 23), which is a plausible mechanism for OpenAI's Ramp adoption-rate to accelerate materially in September after three months of near-flat gains — but this evidence is about spend/token share, not yet the "% of businesses transacting" adoption metric the market resolves on, so the case remains a mechanism/leading-indicator rather than a confirmed data point. NOT FOUND: No Ramp AI Index release with the actual September adoption-rate percentage (expected mid-October, likely before the Oct 17 close); no direct Ramp confirmation that Astra's spend surge has yet moved the overall "% of businesses transacting with OpenAI" figure above 40.5%.

**Mechanism: the required jump is far outside recent measured volatility** - [2026-09-09] The percentage-point deltas Ramp has reported for OpeanAI over the last three published months are 0.09, 0.23 and -0.1/0.23 — essentially micro-moves — and Ramp's own text frames the trend explicitly as continuing deceleration, not reacceleration: "OpenAI underperformed overall AI adoption, rising only 0.09 percentage points to 39.8% of businesses. In general, new AI adoption continues to grow but is decelerating." Reaching above 40.5% in the next reading would require a jump roughly 3–8x any of these recent monthly moves. **Astra hype is a spend-share story, not a breadth-of-adoption story — the two metrics the market conflates** - [2026-09-21] The most-cited "OpenAI gaining" evidence is a spend-share statistic, not Ramp's business-count adoption rate: "OpenAI accounted for roughly 13% of enterprise AI spending tracked by Ramp, compared with around 8% for Anthropic's Claude" — this is dollars concentrated among existing large customers, distinct from the "% of businesses with any OpenAI transaction" figure the Kalshi contract resolves on. - [2026-09-09] FourWeekMBA's direct read of the Ramp release explicitly warns against conflating these metrics: "All figures are Ramp's own, drawn from Ramp's corporate-card and bill-pay customer base. Not U.S.-wide market share. Not revenue share." A concentrated spend surge among already-adopted enterprise accounts does not mechanically add new businesses to the adoption denominator. **Astra's premium pricing works against broadening adoption among the marginal/smaller businesses that drive the Ramp index** - [2026-09] Astra launched at a steep premium — "GPT-6 Astra launched September 3, 2026: $10/$50 per million tokens, 1M context, gated cyber capabilities" — roughly 2.5x the price of OpenAI's own standard model, which cuts against the documented trend of businesses migrating toward cheaper, standard-tier models that Ramp says is driving current volume growth, not toward pricier frontier options. **Rollout friction limits how much of September the new model was actually broadly usable** - [2026-09] Access to Astra was staged and admin-gated rather than instantly available business-wide: "Enterprise access is off by default until an admin enables it" , and even Sam Altman acknowledged rollout problems, with OpenAI's own account posting "It might take a few days to roll out to our Plus and Business users" — meaning much of the September measurement window occurred before Astra was broadly accessible to the SMB/mid-market base that Ramp's dataset skews toward. **Sample composition dampens frontier-driven swings** - [2026-09] Analysts note Ramp's dataset is "a sample skewed toward startups, small and mid-sized companies, and tech-forward buyers" rather than the largest enterprises most likely to adopt a premium-priced, cybersecurity-gated model like Astra first — reducing the odds that Astra's early buzz shows up quickly in the broad adoption-rate metric. **Timing/technicality risk: the true September figure won't exist until after most of the trading window closes** - [2026-09-24] As of today no Ramp release with actual September data exists; based on Ramp's own publication cadence (each report drops on the 9th of the following month, confirmed by the Aug-data report published Sept 9), the true September number is expected only in early-to-mid October — leaving only a few days between that release and the October 17 close for the market to react, and no room for a second data point to confirm a trend reversal before resolution. **No independent adoption-rate (business-count) data source shows a post-Astra breadth jump** - [2026-09] Coverage of Astra's competitive gains cites only OpenRouter developer spend and Ramp's 13% enterprise spend-share figure — both dollar/usage metrics — with no source found reporting a jump in the "% of businesses transacting with OpenAI" breadth metric since Astra's launch. BOTTOM LINE: The strongest NO case rests on (1) three consecutive months of near-flat OpenAI adoption-rate gains (0.09–0.23pp) against Ramp's own explicitly decelerating-adoption narrative, and (2) a clear distinction between the spend-share/OpenRouter metrics fueling "OpenAI is gaining" headlines and the actual business-count adoption-rate metric the market resolves on, which historically moves much more slowly and has shown no confirmed post-Astra breadth increase. NOT FOUND: No Ramp report with actual September 2026 adoption-rate data (expected only in October, after most of the trading window has elapsed); no independent business-count (as opposed to spend-share) data confirming any Astra-driven jump in OpenAI's Ramp adoption rate; no Kalshi order-book/pricing data specific to this contract.