Microsoft Seeks at Least $25B in First Bond Sale Since 2017

Microsoft filed a preliminary prospectus supplement with the SEC on 29 October 2026 for a sale of ten series of notes: two floating-rate series and eight fixed-rate series, with J.P. Morgan, UBS Investment Bank and Wells Fargo Securities as joint book-running managers. The sizes, coupons and maturities are left blank in the filing. A Bloomberg headline the same morning read “Microsoft Looks to Raise at Least $25 Billion From US Bond Sale”, and newswire posts on X described it as Microsoft’s first US high-grade bond sale since 2017.

By our arithmetic, $25 billion of new notes would equal about 70% of the $35.5 billion of total debt Microsoft lists in the prospectus supplement’s capitalization table as of 30 September 2026. It comes one day after chief financial officer Amy Hood said on the earnings call that Microsoft “will access additional sources of funding when we believe it is attractive to do so”.

Short explainer · Microsoft bond sale

A vertical news Short narrated from the published headlines and opening lines of this piece.

Business Pill · Tranches Explained

An evergreen Business Engineer explainer on how debt is split into tranches. It explains the general idea only and does not discuss Microsoft or this sale.

What the Filing Says

The prospectus supplement says the net proceeds “will be used for general corporate purposes, which may include, among other things, funding for working capital, capital expenditures, repurchases of our capital stock, acquisitions and repayment of our existing debt”. The floating-rate notes pay Compounded SOFR plus a spread and cannot be redeemed before maturity; the fixed-rate notes can be redeemed at Microsoft’s option.

The capitalization table lists Microsoft’s existing notes as of 30 September 2026, from the 3.300% notes due 2027 to the 3.041% notes due 2062, and total debt of $35,481 million against total stockholders’ equity of $470,509 million. The 10-Q filed on 28 October says Microsoft’s long-term unsecured debt rating was AAA.

What Was Posted on X

The newswire account @DeItaone posted at 11:33 UTC on 29 October 2026 that Microsoft had kicked off a 10-part US dollar high-grade bond offering. Two minutes later the same account posted that it was Microsoft’s first US high-grade bond sale since 2017. This piece checks the offering against Microsoft’s preliminary prospectus supplement filed with the SEC the same morning.

Wall St Engine posted at 11:54 UTC on 29 October 2026 that Microsoft looks to raise at least $25 billion from a US bond sale, a figure the account did not source.

Milk Road AI says Microsoft is looking to raise at least $25 billion in a 10 part United States investment grade bond sale, its first United States high grade bond deal since 2017, and reads it as a sign the AI buildout is getting bigger.

The Quarter Before the Sale

Hood said in her prepared remarks that capital expenditures were $45.2 billion in the September quarter, including finance leases of $7.4 billion, and that “roughly three quarters of our capex was for short-lived assets, primarily CPUs and GPUs”. She said cash flow from operations was $58 billion and free cash flow was $18.6 billion, and that Microsoft returned $10.2 billion to shareholders through dividends and share repurchases. Our piece on the 75% of capex tied to short-lived chips has the split.

The 10-Q’s cash flow statement shows $4,850 million of debt repayments in the quarter. Its balance sheet shows cash, cash equivalents and short-term investments of $64,509 million on 30 September, against $76,843 million on 30 June. By our arithmetic that is $12.3 billion, or 16%, lower in one quarter, and total debt fell from about $40.3 billion to $35.5 billion.

The Sale Against Microsoft’s Own Figures

By our arithmetic, at least $25 billion of new notes would equal about 55% of the quarter’s $45.2 billion of capital expenditures, about 1.3 times its $18.6 billion of free cash flow and about twice the $12.3 billion fall in cash and short-term investments. It would lift total debt from $35.5 billion to roughly $60.5 billion before issuance costs.

The 10-Q also says Microsoft had “additional leases, primarily for datacenters, that had not yet commenced of $364.6 billion”, commencing between fiscal 2027 and fiscal 2034. By our arithmetic, $25 billion is about 7% of that amount. Our piece on the $365 billion of unstarted leases sets those commitments against Microsoft’s cash, and our piece on Hood’s capex view covers her funding remark.

Where It Sits in the AI Debt Market

Microsoft is the latest large technology company to borrow in the bond market this year. Our piece on record bond sales covers Alphabet raising $147 billion in 2026, and our piece on data-center bond yields covers what lower-rated data-center borrowers are paying.

The Structural Read

As we read the filing, Microsoft gives general corporate purposes, including capital expenditures, as the use of proceeds, and leaves every amount, coupon and maturity blank.

By our arithmetic, $25 billion is about 55% of the $45.2 billion of capital expenditures Hood reported for the September quarter and about 1.3 times its $18.6 billion of free cash flow.

As we read the 10-Q, the sale follows a quarter in which Microsoft repaid $4,850 million of debt and its cash, cash equivalents and short-term investments fell from $76,843 million to $64,509 million.

Three Implications

FOR BOND INVESTORS The 10-Q says Microsoft’s long-term unsecured debt rating was AAA, and the prospectus supplement lists two floating-rate series and eight fixed-rate series.

FOR MICROSOFT’S BALANCE SHEET By our arithmetic, $25 billion of new notes would lift total debt from $35.5 billion to roughly $60.5 billion before issuance costs, against $470,509 million of stockholders’ equity.

FOR THE AI BUILD The 10-Q lists $364.6 billion of leases, primarily for datacenters, that had not yet commenced; by our arithmetic $25 billion is about 7% of that amount.

The Business Engineer Lens

This story maps onto the Business Engineer framework The AI Capex Map.

The framework sets out to map the financing of AI: “How the money flows, where it cracks, what it buys, who can absorb it, and what happens when revenue can’t catch up.”

As we read it, Microsoft’s filing is about the “how the money flows” part: a company that funded its build from operating cash now adding bonds. The framework was published in May 2026 and does not discuss this sale.

Update, 29 Oct (afternoon): the last time Microsoft did this, it raised $17 billion. Microsoft’s final prospectus supplement of 31 January 2017 shows that deal totalled $17,000,000,000 across its series, and Bloomberg reported it at the time as a $17 billion sale. On Microsoft’s 28 October call, CFO Amy Hood said: “In Q2, we expect CapEx spend will be over $50 billion. Therefore, for the calendar year, spend should be approximately $170 billion.” Today’s preliminary prospectus supplement says net proceeds will be used for general corporate purposes, which may include working capital, capital expenditures, repurchases of its capital stock, acquisitions and repayment of existing debt. By our arithmetic, at least $25 billion would be about 1.5 times the 2017 deal and about half of the more than $50 billion of capex Microsoft expects this quarter. As of about 13:50 UTC, EDGAR showed no final prospectus supplement or pricing term sheet, so the series amounts, maturities and coupons are not yet public.

What Is Not Established

The size of the sale comes from a Bloomberg headline we read in syndication, not from the filing or the full article; the prospectus supplement leaves every amount, coupon and maturity blank. The description of the sale as Microsoft’s first US high-grade offering since 2017 comes from the Bloomberg headline’s web address and newswire posts on X, not from the filing.

The filing gives general corporate purposes, including capital expenditures, as the use of proceeds; it does not tie the notes to a particular data center or lease. The ratios above use the $25 billion minimum and are our arithmetic. Pricing and final sizes are expected in a final prospectus supplement.

The Bottom Line

Microsoft filed on 29 October for a ten-part bond sale, which a Bloomberg headline put at at least $25 billion and newswire posts called its first US high-grade sale since 2017. By our arithmetic, that minimum would add about 70% to the $35.5 billion of debt it reported on 30 September, after a quarter in which its cash and short-term investments fell by $12.3 billion and its capital expenditures reached $45.2 billion.