Thirty large AI-exposed stocks lost a combined $3.17 trillion of market value in October, from $37.53 trillion at the end of September to $34.36 trillion at the close on 30 October, an 8.5% fall by our arithmetic. Only four of the 30 rose.
Alphabet, Google’s parent, and Nvidia together lost $1.35 trillion, 43% of the total. The gainers were Tesla, Apple, Microsoft and IBM, and the month ended on the day Apple passed Nvidia as the most valuable company.
Business Pill · Power Law
A short Business Engineer explainer on power laws, where a few outcomes account for most of the value. It teaches the general idea only and does not discuss the companies in this story.
The key insight: By our arithmetic, 30 AI-exposed stocks lost $3.17 trillion in October; Alphabet and Nvidia were 43% of the fall, and only four of the 30 rose.
By our arithmetic, Alphabet lost $780.2 billion (18.5%), Nvidia $572.1 billion (10.4%), Intel $289.5 billion (45.3%), Meta $281.7 billion (15.2%) and Micron $204.1 billion (16.9%). Those five account for $2.13 trillion, or 67% of the group’s fall.
Memory makers fell together: Micron, SK Hynix and Samsung Electronics lost a combined $549.5 billion. Chip-equipment makers Applied Materials, Lam Research, KLA and ASML lost $350.9 billion between them.
The steepest percentage falls were Intel at 45.3%, CoreWeave at 37.0%, Arm at 28.9% and Lam Research at 27.2%. Intel’s shares fell 28.6% on 30 October alone after its results, as we reported on Friday.
Change in market value from 30 September to 30 October 2026 for the five biggest falls and the five best results among 30 AI-exposed stocks we selected. Our arithmetic from Yahoo Finance closing prices and SEC filing cover share counts (Samsung and SK Hynix: Yahoo Finance share counts). FourWeekMBA.
The Four That Rose
Tesla added $177.9 billion (12.7%), Apple $169.4 billion (3.5%), Microsoft $66.9 billion (1.8%) and IBM $35.8 billion (17.2%), by our arithmetic. Salesforce was close to flat, down $0.3 billion.
The Business Lever: Where the Losses Sat
As we read the split, the losses were heaviest in the companies most tied to AI hardware: chips, memory and chipmaking equipment. Of the three largest US cloud providers in the group, Microsoft rose while Amazon and Alphabet fell. Alphabet’s loss followed results we covered in Search slipping below half of its revenue.
The 30 stocks are Nvidia, Apple, Microsoft, Alphabet, Amazon, Meta, Broadcom, TSMC, Oracle, AMD, Micron, SK Hynix, Samsung Electronics, ASML, Intel, Palantir, CoreWeave, Arm, Qualcomm, Dell, Super Micro, Vertiv, Applied Materials, Lam Research, KLA, Cisco, IBM, Salesforce, ServiceNow and Tesla. The selection is ours. Market values here are our arithmetic: each company’s closing price, from Yahoo Finance, multiplied by the shares outstanding on the cover of its latest SEC filing, with the same share count used for both dates.
Saudi Aramco, Samsung Electronics and SK Hynix use Yahoo Finance share counts, and prices outside the US are converted at the day’s exchange rate.
The Structural Read
As we read the split, the heaviest losses sat in chips, memory and chipmaking equipment: Micron, SK Hynix and Samsung lost $549.5 billion and four equipment makers $350.9 billion, by our arithmetic.
As we read the list of gainers, Microsoft rose while Amazon and Alphabet fell, so the month split the largest cloud providers.
AppleInsider
“has been going back and forth between Apple and Nvidia for some time now, as iPhone and Services demand go up against AI chip consumption”
Three Implications
FOR CHIP SUPPLIERS Intel fell 45.3%, Arm 28.9% and Lam Research 27.2% in October, by our arithmetic.
FOR MEMORY MAKERS Micron, SK Hynix and Samsung Electronics lost a combined $549.5 billion, by our arithmetic.
FOR THE GAINERSTesla added $177.9 billion and Apple $169.4 billion, by our arithmetic.
The framework says the AI Supercycle has “a dual character that is simultaneously a bubble and a supercycle”.
As we read it, a month in which 26 of 30 AI-exposed stocks fell, led by chips and memory, shows the bubble side of that dual character in market values. The framework predates these figures and does not discuss them.
These are closing-price snapshots on two dates, not total returns, and the group is our own selection of AI-exposed companies, not an index. Share counts come from each company’s latest filing and are not adjusted for changes during October.
This Week In The AI Supercycle
Anthropic’s Reality Check, The Capital Squeeze, & The New World Order
This week’s issue: for two years the AI build-out was priced as a growthstory. This week it started being priced as a credit story.
Thirty AI-exposed stocks lost about $3.17 trillion of market value in October, by our arithmetic, with Alphabet and Nvidia accounting for 43% of the fall and only four of the 30 ending the month higher.
A note on sourcing. Market values are our arithmetic: Yahoo Finance closing prices multiplied by shares outstanding from each company’s SEC filing cover (Yahoo Finance share counts for Saudi Aramco, Samsung Electronics and SK Hynix), converted to US dollars at the day’s exchange rate where needed. They are snapshots, not total returns, and not investment advice.
Gennaro Cuofano is a CRO and tech executive who has worked in AI since late 2015, starting with bringing NLP, natural-language generation, voice and chatbot products to the marketing industry. His background is in law and finance: he holds a Master's degree in Law and an International MBA with an emphasis on corporate finance (LUISS Business School and the University of San Diego, 2012), and worked as a financial analyst at a real-estate investment firm in San Diego and as an assistant controller. His work focuses on business model strategy, business engineering and, more broadly, structural analysis: how companies make money, read from their own filings. He created FourWeekMBA and leads research there and at The Business Engineer, his newsletter on AI and business strategy, with over 95,000 subscribers and more than 1,000 published analyses. His writing has also appeared on Entrepreneur (for example, How to Digitize a Family Business in Europe) and HackerNoon. Find him on LinkedIn and Substack. See how we source.
