Meta, Alphabet, Microsoft and Amazon lost about $665 billion of market value in the first trading session after each released its third-quarter results, by our arithmetic from daily closing prices and the share counts on their 10-Q filings. Alphabet accounted for $496.5 billion of it, about 75%.
That is more than the other three combined: Meta lost $124.4 billion, Amazon $37.2 billion and Microsoft $6.5 billion, by our arithmetic.
Short explainer · Big Tech’s $665B post-earnings loss
A vertical news Short summarising this story. Figures come from daily closes and each company’s 10-Q share counts; our arithmetic is labelled.
Business Pill · Free Cash Flow
A short explainer on free cash flow. It teaches the general idea only and says nothing about these market-value figures.
The key insight: By our arithmetic, Meta, Alphabet, Microsoft and Amazon lost about $665 billion of market value in the first session after their third-quarter reports, and Alphabet’s $496.5 billion was about 75% of it.
All four companies released results after the US market close, according to the timestamps on their Form 8-K filings on SEC EDGAR: Meta on 21 October, Alphabet and Microsoft on 28 October and Amazon on 29 October. We compared each company’s close before its report with the close of the next trading day, and multiplied by the shares outstanding on the cover of its third-quarter 10-Q.
For Alphabet, we valued its 5,888 million Class A and 827 million Class B shares at the Class A close and its 5,579 million Class C shares at the Class C close, using the counts in its 10-Q. Meta’s 10-Q lists 2,214,472,367 Class A and 341,768,886 Class B shares.
Market value lost by Meta, Alphabet, Amazon and Microsoft in the first trading session after each company’s Q3 2026 report, from daily closing prices and the share counts on each 10-Q cover; our arithmetic.Animated: combined market value of Alphabet, Amazon, Meta and Microsoft against the 23 October close, by trading day to 30 October, from daily closes and 10-Q share counts; our arithmetic. This calendar-week view (minus $662 billion) differs from the first-session-after-earnings total in the text because Meta reported on 21 October.
What Was Posted on X
THIS IS MASSIVE:
The 4 largest hyperscalers erased a combined -$894 billion in market cap this week following their earnings results.
Alphabet, $GOOGL, accounted for the largest loss at -$505 billion, followed by Amazon, $AMZN, at -$192 billion, and Meta, $META, at -$187 billion.
Alphabet came under particularly heavy pressure, plunging -12.6% on Thursday in its worst session on record and losing $525 billion in market value after Search revenue missed expectations and management signaled another significant increase in investment for 2027.
Meanwhile, slowing growth in core businesses and increasingly negative free cash flow are raising questions about whether these enormous AI infrastructure investments can generate sufficient returns.
To put it simply, investors are no longer rewarding ever-higher spending alone, unlike in previous quarters.
They are now demanding clearer evidence that the AI buildout can translate into sustainable revenue and profitability.
The AI trade is shifting from rewarding investment to demanding tangible returns.
— Global Markets Investor (@globalmktobserv) Nov 01 11:23
An X account posted a Financial Times chart, sourced to FactSet and FT research, on 1 November. The chart puts the combined market-value loss of Meta, Google, Microsoft and Amazon after their earnings at $894 billion. Our own recount from closing prices and 10-Q share counts is lower, at about $665 billion for the first session after each report.
Alphabet’s Day
Alphabet’s Class A shares fell 12.6% on 29 October, from $324.89 to $283.82. Its market value went from about $3.98 trillion to about $3.48 trillion, by our arithmetic. The Motley Fool calls the drop the largest single-session percentage decline in Alphabet’s history.
On the earnings call, chief financial officer Anat Ashkenazi said: “We continue to expect our capex to increase significantly in 2027, and we’ll provide further details on our Q4 call”. She said the 2026 range of $195-$205 billion “remains unchanged”. Our earlier piece covers Search falling below half of Alphabet’s revenue.
The Other Three
Meta fell 7.0% on 22 October, from $697.52 to $648.85. Amazon fell 1.4% on 30 October, from $243.79 to $240.35, and Microsoft 0.2% on 29 October, from $531.01 to $530.14. The percentages are changes in each company’s closing price.
Measured from each pre-report close to the close on Friday 30 October, the four lost about $862 billion, by our arithmetic: Alphabet $546.1 billion, Meta $211.0 billion, Microsoft $67.6 billion and Amazon $37.2 billion.
A Bigger Number on X
A Financial Times chart shared on X on 1 November, sourced to FactSet and FT research, puts the four companies’ combined loss at $894 billion, with Meta at $187 billion and Amazon at $192 billion. Our first-session recount is lower, mainly for Meta and Amazon. The chart does not state the exact dates or share counts it used.
The Business Lever: How Far Apart the Four Moves Were
As we read the closes, the market separated the four companies rather than selling them evenly: Alphabet, whose chief financial officer said she expects capex to rise significantly in 2027, lost 12.5% of its value in a session, while Microsoft lost 0.2%. Our earlier work shows the five largest spenders’ free cash flow turned negative, to minus $31.8 billion combined in the third quarter, and the cost of insuring their debt has risen.
The Structural Read
As we read the closes, the four moves were far apart: Alphabet’s market value fell 12.5% in one session, Meta’s 7.0%, Amazon’s 1.4% and Microsoft’s 0.2%, by our arithmetic.
As we read the timing, Alphabet and Microsoft reported within minutes of each other on 28 October, according to their 8-K timestamps, and the next session left Alphabet $496.5 billion lower and Microsoft $6.5 billion lower, by our arithmetic.
As we read the gap with the FT chart’s $894 billion, most of the difference sits in Meta and Amazon: our first-session recount gives $124.4 billion and $37.2 billion, against the chart’s $187 billion and $192 billion.
Anat Ashkenazi, Alphabet CFO, on the Q3 2026 earnings call
“We continue to expect our capex to increase significantly in 2027”
Three Implications
FOR INVESTORS By our arithmetic, the four lost about $862 billion from their pre-report closes to the close on Friday 30 October.
FOR ALPHABET Its Class A shares fell 12.6% on 29 October, from $324.89 to $283.82; the Motley Fool calls it the largest single-session percentage decline in Alphabet’s history.
FOR CAPEX WATCHERS Alphabet’s CFO said the 2026 capex range of $195-$205 billion remains unchanged and that she expects capex to increase significantly in 2027.
The framework says “It is a sovereign-scale financing problem dressed in tech-company clothing — and the financial architecture is starting to invert.”
As we read the closes, Alphabet’s market value fell 12.5% in one session, by our arithmetic. The framework is the owner’s argument and does not discuss these figures.
Market moves have many causes, and we do not attribute any company’s fall to a single item in its report. Our figures use closing prices and the share counts on each 10-Q cover, which are dated in October; they are not FactSet’s figures. Meta reported a week before the others, so the four sessions are not the same day.
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By our arithmetic, Meta, Alphabet, Microsoft and Amazon lost about $665 billion of market value in the first session after their third-quarter reports, and Alphabet’s $496.5 billion was about 75% of it. Through Friday 30 October the four were down about $862 billion from their pre-report closes.
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A note on sourcing. Closing prices come from Yahoo Finance and Nasdaq.com; share counts from each company’s third-quarter 10-Q cover and report timing from their Form 8-K filings on SEC EDGAR; the Ashkenazi quotes from Alphabet’s earnings call. We did not contact the companies. Every market value and change is our arithmetic.
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.
