What was filed
Anthropic filed its Form S-1 with the SEC on October 26, 2026. The filing seeks to list Class A common stock on the Nasdaq Global Select Market under the ticker ANT. The price range and share count are still blank. Reports point to a mid-November listing. That timing is reported, not part of the filing. This is a registration step, so no shares are trading yet.
The numbers that matter
The S-1 shows an operating loss of $693 million in H1 2026, against $2,135 million in H1 2025. Net loss was $80,748 million, against $12,969 million. Revenue was about $16.3 billion for the half, up from $1.2 billion a year earlier.
The quarterly split is notable. Q1 2026 showed an operating loss of $1,667 million. Q2 2026 showed operating income of $974 million on $11,555 million of revenue. That makes Q2 the first operating-profit quarter among the six quarters the filing shows. One quarter does not establish a trend.
Why the net loss is mostly accounting
Roughly $72.4 billion of the loss traces to revaluing convertible notes and similar instruments as the company's worth climbed. The cash-flow statement adds $8.72 billion in noncash charges on other financial instruments. In plain terms, the higher Anthropic's valuation goes, the more its convertible notes are worth. Under fair-value accounting, that increase is booked as an expense.
Kepler's analysis of the filing gives more detail:
- The largest single quarterly charge was $59.6 billion, in the June quarter alongside the Series H financing.
- At June 30, the convertible notes outstanding were all issued to Amazon. They carried $6.2 billion of principal at a fair value of $108.6 billion.
- Kepler also reports that operating cash flow was positive at $3.9 billion for the half.
The caveats matter:
- "Noncash" does not mean "costless." The notes convert into equity, so the cost lands on shareholders through dilution.
- Operating loss excludes many items, so it is not the same as overall profitability.
- Other commentators note that the filing's $693 million operating loss is not a measure of cash burn.
The compute bill is the real exposure
Compute is where cash goes. Compute and infrastructure costs rose to $8.95 billion from $2.33 billion. Kepler's reading is that agreements with seven compute providers total about $637 billion. About $431 billion of that is minimum spend or lease rent, and the rest is "up to" or pay-on-delivery amounts. The $431 billion is owed whether or not revenue keeps up. Commitments, expenses recognized and cash paid are different things, so these totals should not be read as money already spent.
The Microsoft angle
This is why the story belongs on a Microsoft-focused site.
Azure is a compute supplier. WION reports the filing includes a commitment of $44.9 billion to Microsoft Azure through May 2033. An earlier draft-filing report from ZeroHedge cited $31 billion for Microsoft. The two figures differ, and the filing text I could inspect did not settle it. Treat the Azure number as unconfirmed until you check the final S-1.
Azure Marketplace is a sales channel. Kepler reports that customers can buy Claude directly or through the AWS, Google Cloud and Microsoft Azure marketplaces. Anthropic holds the customer contract in either case. Those marketplaces handled 48% of first-half 2026 revenue.
Microsoft is also a competitor. According to Dealroom's summary of the draft filing, Anthropic says it struggles to secure enough compute from AWS, Google and Microsoft because those hyperscalers increasingly treat it as a competitor rather than a customer. Kepler adds that the filing flags the risk that these overlapping roles could affect access to compute, its price, or how Anthropic's workloads are prioritized.
What this means for IT and developers
My analysis, not a claim from the filing:
- Vendor risk is now documented. Anyone building on Claude through Azure now has a public disclosure of the partner-versus-rival tension. It is a procurement risk to weigh, not a prediction of outages.
- Prices and availability are not addressed. Nothing in the filing shows that Claude prices will rise or that service will change. That would need separate evidence.
- Concentration is a factor. Kepler reports the top five customers produced about 25% of revenue in the first nine months of 2026. Dealroom's summary says about 20% of revenue came from two customers.
- Financing has conditions. Kepler reports note purchase agreements giving up to $77 billion of potential financing, subject to conditions.
Bottom line
The claim that Anthropic doesn't lose as much as you think holds up if you read it narrowly. The first-half operating loss was $693 million, not $80.7 billion, and the net-loss headline is mostly fair-value accounting. It is not a claim that the company is profitable. A GAAP loss is still reported, and the compute commitments are enormous. Final IPO pricing and valuation remain unknown. For Microsoft shops, the Azure ties in compute and marketplace sales are the part to watch.