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

- [2026-09-09] Ramp published its "September 2026 AI Index" letter (which, per Ramp's reporting lag convention, covers August transaction data): In August, Anthropic extended its lead in business AI adoption, with 43.8% of U.S. businesses paying for Anthropic (up 0.34 points MoM), while OpenAI rose only 0.09 percentage points to 39.8% of businesses . Source: https://ramp.com/data/ai-index-sept-2026 - [2026-09-09] The same letter notes new AI adoption continues to grow but is decelerating , and per-employee AI spend among top spenders fell, a theme the economist calls "Cracks in the AI Thesis." Source: https://ramp.com/data/ai-index-sept-2026 - [prior month, published ~2026-08-xx] The August 2026 letter (covering July data) showed 43.5% of U.S. businesses paid for Anthropic (up 1.1 points MoM), while OpenAI rose only 0.23 percentage points to 39.7% of businesses , confirming the month-over-month OpenAI growth has been well under 1 percentage point for at least two consecutive reporting cycles. Source: https://ramp.com/data/ai-index-august-2026 - [2026-05-13] Earlier in the year OpenAI adoption had been more volatile: the May letter (April data) showed Anthropic rising 3.8pp to 34.4% while OpenAI fell 2.9pp to 32.3%, with overall adoption at 50.6% , illustrating that larger swings (>1pp) are possible but have not recurred recently. Source: https://ramp.com/data/ai-index-may-2026 - [2026-09-16] A third-party analysis (FourWeekMBA) of the Sept 9 release reports the headline figures as 43.8% Anthropic business penetration (+0.34pp MoM) and 39.8% OpenAI business penetration (+0.09pp MoM) , plus a broader shift in token mix away from frontier models. Source: https://fourweekmba.com/ai-ramp-ai-index-enterprise-frontier-pacing-demand-side/ - [2026-09-22] Secondary coverage (kucoin) of the September letter reiterates Anthropic held 43.8% of the U.S. enterprise AI paid market in August, up 0.34 percentage points from July, while OpenAI's share rose to 39.8%, an increase of 0.09 percentage points , and flags slowing overall AI-adoption growth. Source: https://www.kucoin.com/news/flash/ramp-report-anthropic-holds-43-8-of-u-s-enterprise-ai-paid-share-in-august - [2026-09-23] A crypto-news summary of Ramp's newly expanded weekly token-spend dashboard still cites the same monthly figure, as of August 2026, Anthropic held a 43.8% share of business AI adoption among Ramp's client base, compared to OpenAI's 39.8% , indicating no newer official "adoption rate" figure (i.e., for September) had been published as of that date. Source: https://cryptobriefing.com/ramp-ai-index-token-spend-volumes-update/ - [2026-09-29] A separate analysis parsing Ramp's raw public dataset (token spend, not the monthly "adoption rate" metric) covers usage through 20 September 2026, drawn from 3,768 rows spanning January 2025 to September 20, 2026 — this is a different, more granular token-spend series and not the monthly adoption-rate figure the question references. Source: https://fourweekmba.com/ai-openai-anthropic-ramp-token-spend-september-2026/ - [2026-09-29 note on methodology] This analysis stresses the index contains exactly two model makers — OpenAI and Anthropic. There is no Google, no Meta, no open-source , underscoring that Ramp's published monthly "adoption rate" (the metric this market tracks) is a distinct, separately-reported series from the token-spend dataset. Source: https://fourweekmba.com/ai-openai-anthropic-ramp-token-spend-september-2026/ - [2026-09-01 to 2026-09-29, pattern] Based on Ramp's established publishing cadence (letters released ~day 9 of the following month, e.g. August letter on Aug 9ish for July data, September letter on Sept 9 for August data), the "September 2026" OpenAI adoption figure that this market resolves on is expected to first appear in an "October 2026 Ramp AI Index" letter, likely published around 2026-10-09 to 2026-10-14 — before the market's 2026-10-17 close. Source: https://ramp.com/data/ai-index-sept-2026 (pattern inferred from publication dates across months) - [as of 2026-10-01] No October 2026 Ramp AI Index letter (covering September data) has yet been published; the latest confirmed official OpenAI adoption figure remains 39.8% (August data, published Sept 9, 2026). Source: https://ramp.com/data/ai-index-sept-2026 BOTTOM LINE: The most recent two official monthly readings show OpenAI adoption at 39.7% (July) and 39.8% (August), with month-over-month gains decelerating to roughly +0.1–0.2 percentage points amid a broader "cracks in the AI thesis" slowdown narrative; reaching above 40.5% for September would require a jump (~+0.7pp) far larger than the recent trend, though the actual September figure has not yet been published and is expected via an October letter before the market closes. NOT FOUND: No official Ramp AI Index letter for "September 2026 data" (i.e., the one that would be titled "October 2026 Ramp AI Index") had been published as of 2026-10-01; exact publication date for that letter could not be confirmed, only inferred from the recurring ~9th-of-month cadence.

- [2026-09-09] Ramp's August-2026 data (published in the "September 2026 Ramp AI Index" letter) showed OpenAI business adoption rising only 0.09 percentage points to 39.8% of businesses , while Anthropic rose to 43.8%. https://ramp.com/data/ai-index-sept-2026 - [2026-09-09] The same letter frames the trend as a slowdown: "In August, Anthropic extended its lead in business AI adoption. 43.8% of U.S. businesses paid for subscriptions or tokens from Anthropic, up 0.34 percentage points month over month." OpenAI's gain was far smaller. https://ramp.com/data/ai-index-sept-2026 - [2026-08-xx] One month earlier (July data), OpenAI adoption was 43.5% of businesses versus OpenAI at 39.7% , meaning OpenAI rose only ~0.1–0.2pp between July and August. https://ustechautomations.com/resources/blog/ramp-ai-index-explained-what-it-changes - [2026-06-10] After a mid-year methodology revision, Ramp reported OpenAI "OpenAI was essentially flat, declining 0.1 percentage points to 39.5% of businesses. Anthropic rose 2.5 percentage points to 41.0%" , establishing OpenAI's current ~39-40% plateau. https://econlab.substack.com/p/how-much-does-it-cost-to-be-ai-pilled - [2026-05-13] Before the methodology revision, OpenAI had fallen sharply: "Anthropic adoption rose 3.8% in April to 34.4% of businesses while OpenAI adoption fell 2.9% to 32.3%" — the first Anthropic/OpenAI crossover, showing OpenAI's rate can move several points in a single month under stress. https://ramp.com/leading-indicators/the-ai-race-has-a-new-frontrunner-but-no-clear-winner - [2026-03-xx] Earlier in 2026, OpenAI similarly had a large single-month drop: "OpenAI's 1.5% decline was the largest in any single month for any AI model company since we started tracking business AI adoption" (reporting February 2026 data). https://ramp.com/data/ai-index-march-2026 - [2025-12-xx] By contrast, OpenAI has also posted large positive swings historically, e.g. December 2025 data showed it "reached a new record-high, growing adoption by two percentage points to 36.8% of businesses" , so multi-point moves are within Ramp's historical range, just not in the last three reported months. https://econlab.substack.com/p/the-census-bureau-was-undercounting - [2026-09-29] A third-party parsing of Ramp's raw token-spend dataset (a different metric — token-spend share between OpenAI and Anthropic only, not the headline "adoption rate") found OpenAI's share of combined OpenAI+Anthropic token spend rising to 44.9% in September, "38.0% in July, 37.7% in August, and 44.9% in September — the highest" ; this is not the same series the Kalshi question references (business adoption %), and should not be conflated with it. https://fourweekmba.com/ai-openai-anthropic-ramp-token-spend-september-2026/ - [2026-09-20] Independent coverage of the live Ramp dashboard as of late September still cites August figures (39.8% OpenAI business-adoption share) as the latest official monthly reading; no September monthly business-adoption figure had been published as of month-end September. https://cryptobriefing.com/ramp-ai-index-token-spend-volumes-update/ BOTTOM LINE: Over the last three published monthly readings (June–August 2026), Ramp's headline "OpenAI business adoption rate" has been essentially flat in the 39.5%–39.8% band, with month-over-month gains of only ~0.1–0.3 percentage points, well short of the ~0.7pp jump needed to clear 40.5% in September; while OpenAI has shown larger (both positive and negative) multi-point swings in the past, the most recent trend and Ramp's own commentary on "decelerating" OpenAI growth make a jump above 40.5% in the next reading a low-base-rate event. NOT FOUND: No September-2026 monthly "business adoption rate" figure for OpenAI has been published yet (as of 2026-10-01); Ramp's regular monthly letter reporting September data was not found in search results, so the actual market-settling figure is not yet available.

YES means: Ramp AI Index's first-published "September 2026" OpenAI business-adoption figure (expected in Ramp's October letter, likely ~Oct 9–14, before the Oct 17 close) comes in above 40.5% of U.S. businesses, implying OpenAI gained roughly +0.7pp or more month-over-month versus August's 39.8%. - [2026-09-29] Axios/Invezz reporting shows OpenAI's annualized revenue run rate is nearing $70 billion, up more than 70% since the start of the third quarter, as enterprise sales more than doubled since July, with business-to-business revenue growing more than 100% over the same period — a far steeper trajectory than Ramp's recent 0.1–0.3pp monthly adoption gains, giving a plausible mechanism for a sharp September re-acceleration in paid business adoption if even a fraction of this B2B surge shows up as new Ramp-tracked subscriptions. - [2026-09-29] The same reporting frames this as Ramp's latest AI Index just showed Anthropic leading adoption among its paid business users for the first time, a 4x adoption surge since 2025 as the competitive backdrop OpenAI is now reacting against — implying management urgency ("code red") that could translate into aggressive September enterprise pricing/packaging pushes. - [2026-09-29] OpenAI held its DevDay on September 29, 2026, presenting new AI features for both enterprises and consumers , with analysts noting rapid growth, with a $70b annualized revenue run-rate and 70% sequential growth as of Q3 '26, and enterprise adoption accelerating, driven by Private Intelligence and enhanced security features — though this event falls at the very end of September and would mostly affect October, not September, Ramp data. - [2026-09-01 to 2026-09-20] A third-party parse of Ramp's granular token-spend dataset (a different series from the headline adoption rate) found OpenAI's share of combined OpenAI+Anthropic token spend jumping to 44.9% in September versus 37.7% in August, the highest level in the series, per earlier-cited analysis — suggesting usage intensity (if not raw subscriber count) swung back toward OpenAI during September, a leading indicator that could foreshadow a stronger adoption-rate print. - [2026-09-09] Ramp's own September letter already flags OpenAI's price cuts as a lever that could pull in price-sensitive new subscribers: OpenAI and Anthropic have both announced a series of price cuts over the last month. Our latest index tracking the effective price per million tokens shows that prices have declined 41% to $0.68 as of this week, down from the 2026 peak of $1.15 in March , a dynamic that could expand the paid-adoption base broadly, including for OpenAI, in September. - [2026-05-13, precedent] Ramp's own history shows large single-month swings are achievable in either direction: the April 2026 data had business AI adoption crossed 50% for the first time in March, reaching 50.4% of businesses… OpenAI adoption fell by 1.5% , and earlier, OpenAI itself posted a two-point monthly gain in December 2025 per the base-rate report, confirming the methodology permits >0.7pp moves when a specific catalyst (e.g., a major model launch or pricing shift) lands squarely within the reporting month. - [2026-09-28] Separately, Anthropic's IPO prospectus disclosed its own cost and risk pressures — Anthropic's full-year 2025 revenue grew twelvefold to nearly $4.6 billion… while its operating loss for the year exceeded $8 billion… Anthropic's prospectus also disclosed $518 billion in future cloud, computing, and infrastructure obligations — which, combined with reports of safety incidents affecting both labs, could cause some price-sensitive or risk-averse enterprise buyers to re-balance spend toward OpenAI in September. BOTTOM LINE: The YES case rests on a real but still-indirect signal — OpenAI's Q3 2026 enterprise *revenue* and token-spend-share surge reported in late September — translating into a corresponding jump in Ramp's narrower "share of businesses paying for OpenAI" metric; no official September Ramp adoption-rate figure exists yet, and the revenue/token-spend surge is not the same series this market settles on, so this remains a plausible but unconfirmed path to YES. NOT FOUND: No official Ramp AI Index "September 2026 data" (October letter) figure has been published as of 2026-10-01; could not confirm whether the reported Q3 enterprise revenue/B2B doubling or the September token-spend-share jump to 44.9% has started flowing into Ramp's distinct "business adoption rate" series, nor the exact publication date of the next letter.

YES means: Ramp AI Index reports OpenAI's U.S. business adoption rate for September 2026 (to be published in Ramp's "October 2026" letter, expected ~Oct 14) as strictly above 40.5%. - [2026-09-09] Ramp's own September letter titled the update "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" , explicitly framing OpenAI's trajectory as weakening, not accelerating, into September. Source: https://ramp.com/data/ai-index-sept-2026 - [2026-09-09] The same letter states plainly that "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." This is the most recent official trend data point available and shows virtually no momentum. Source: https://ramp.com/data/ai-index-sept-2026 - [2026-09-09] Ramp's own economist flagged a structural headwind for frontier spend: "the price of AI is coming down. OpenAI and Anthropic have both announced a series of price cuts over the last month. Our latest index tracking the effective price per million tokens shows that prices have declined 41% to $0.68 as of this week, down from the 2026 peak of $1.15 in March." Falling frontier prices plus the "cracks in the AI thesis" narrative give no indication of an imminent acceleration large enough to add ~0.7pp in one month. Source: https://ramp.com/data/ai-index-sept-2026 - [2026-09-10] Independent coverage confirms the deceleration framing: "The September edition shows AI adoption still growing, but at a slower pace. The companies that spend the most on AI spent less in August than they did the month before." Source: https://the-decoder.com/top-ai-spenders-cut-per-employee-costs-by-nearly-10-percent-in-august/ - [2026-09-10] The same piece notes token share shifting away from frontier models entirely: "The token share of frontier models like Opus and Sol dropped from 53 percent in early August to 45 percent by early September as standard and lite models picked up share." This is consistent with businesses economizing rather than expanding net-new paid adoption of either major lab. Source: https://the-decoder.com/top-ai-spenders-cut-per-employee-costs-by-nearly-10-percent-in-august/ - [2025-09 historical precedent] Ramp's own year-ago September reading for overall paid AI adoption showed an outright decline, not growth: "Paid AI adoption declined in September, for the second time this year. According to Ramp AI Index, The share of businesses paying for AI models and services fell to 43.8% in September, a 0.7% drop." If September carries similar seasonal softness in 2026, that works against any large positive OpenAI jump this cycle. Source: https://econlab.substack.com/p/are-we-in-an-ai-bubble - [2026 pattern] Ramp's economist states the letter is published on a fixed cadence: "I post on Substack first on the second Wednesday of every month at 10 a.m." For October 2026 that falls on Oct 14 — before the Oct 17 close — so the market is very likely to have an official reading in time, removing "no data published" as a path to NO, and placing the full weight of the NO case on the trend itself. Source: https://econlab.substack.com/p/anthropics-breakout-month - [2026-09-16] Ramp's broader September 16 post on "Top SaaS Vendors" and influencer-marketing commentary shows no sign of a major new OpenAI enterprise product or pricing catalyst in September that would be expected to reverse deceleration; coverage from this period centers on cost-cutting and model-mix shifts rather than renewed OpenAI enterprise wins. Source: https://econlab.substack.com/ - [status-quo inertia] Across the last three published monthly readings (39.5% June, 39.7% July, 39.8% August), OpenAI's adoption rate has moved a cumulative ~0.3pp in three months; simple extrapolation of that pace for one more month lands near 39.9%–40.0%, roughly half a point short of the 40.5% threshold, with no catalyst identified in the research above to break that pattern. BOTTOM LINE: Every primary-source data point and the Ramp economist's own "cracks in the AI thesis" framing point to continued deceleration, falling frontier-model prices, and (per the year-ago September precedent) possible seasonal softness — none of which supports a sudden ~0.7pp jump in OpenAI's adoption rate; the trend and stated narrative favor NO. NOT FOUND: No October 2026 Ramp AI Index letter (covering September data) had been published as of this research; its exact publication date is inferred (likely Oct 14, "the second Wednesday") but not yet confirmed, and no reporting suggesting an OpenAI-specific adoption surge in September 2026 was found.