Five companies that did not rank among the top bond issuers in the U.S. investment-grade credit market as recently as 2023 are now on track to rival the country's six largest banks as the biggest borrowers in the index.
Amazon $AMZN, Alphabet $GOOGL, Meta $META, Microsoft $MSFT, and Oracle $ORCL issued $121 billion in U.S. corporate bonds in 2025, compared with an average of $28 billion per year between 2020 and 2024, according to a Bank of America $BAC report. By October 2025, debt tied to AI had reached $1.2 trillion, making it the largest segment in the investment-grade market and, at 14% of the high-grade market, surpassing U.S. banks as the biggest sector in the JPMorgan $JPM U.S. Liquid index, according to M&G Investments.
The numbers mark a structural shift in who borrows at scale in American credit markets, not a one-quarter anomaly. Here's what to know.
The issuance wave, deal by deal
The second half of 2025 was when the shift became visible. Oracle sold $18 billion in bonds in September. Meta followed in October with a $30 billion deal, the largest individual non-M&A high-grade bond sale on record, according to MUFG analysts. Alphabet ($17.5 billion) and Amazon ($15 billion) followed in November. The pace has not slowed. In March 2026, Bank of America raised its full-year hyperscaler issuance forecast to $175 billion from $140 billion after Amazon issued about $54 billion in bonds across U.S. dollar and euro markets. In late April, Meta returned to the market with a $25 billion offering, according to Bloomberg. Alphabet priced about $32 billion in dollar and euro notes earlier this year, including a rare 100-year sterling-denominated bond — the first century bond from a tech company in decades, according to Fortune.
The total matters less than the trajectory. Bank of America expects the Big Five hyperscalers to borrow about $140 billion a year over the next three years, which could exceed $300 billion a year. That pace would put them on par with the Big Six U.S. banks' expected average of $157 billion in annual issuance, according to Reuters.
How the index is changing
The implications for the investment-grade index itself are direct. In the final three months of 2025 alone, Oracle, Meta, Google, and Amazon issued about $90 billion in bonds. As Apollo chief economist Torsten Sløk has projected, financing just 20% of AI capital expenditures through investment-grade markets would "materially reshape index composition," propelling Amazon into the top three issuers and pushing Meta, Microsoft, Oracle, and Google into the top 10, with Google jumping from 67th to eighth.
That projection is already playing out. Alphabet's long-term debt rose to $46.5 billion in 2025, a 328% increase from 2024, according to Macrotrends data. Across the five hyperscalers, on-balance-sheet debt is about $420 billion, according to Fortune, with larger commitments in off-balance-sheet leases. "So the composition of the index will change. It is changing," Jason Greenblath, a senior portfolio manager and director of corporate credit research at American Century Investments, told Quartz recently.
AI-related investments accounted for about 30% of total net issuance in the U.S. dollar-denominated investment-grade market in 2025, according to Christian Hantel, head of global corporate bonds at Vontobel. Vontobel estimates about $300 billion in AI or data center-related bond issuance over the next year, and about $1.5 trillion over the next five years, which would make the AI-related segment 15% to 20% of most corporate bond indexes.
What's financing what
The borrowing is a function of capital expenditures that keep rising. Microsoft, Meta, Amazon, and Alphabet collectively told investors they will spend about $700 billion on capital expenditures in 2026, double what they spent in 2025. Worldwide spending on AI is forecast to total $2.52 trillion in 2026, a 44% increase year-over-year, according to Gartner.
These companies generate enormous cash flow. Operating cash flow for the five hyperscalers is expected to reach $577 billion in 2025, up from $378 billion in 2023. Their debt-to-cash ratio is expected to fall from 0.94 to 0.75, meaning the overall debt burden is getting lighter in relative terms, according to Bank of America. But the math at the margin still forces borrowing.
Capital expenditures at these levels consume most of the cash, and hyperscaler capex in 2026 will consume close to 100% of operating cash flows, compared with a 10-year average of 40%, according to UBS. The bond market fills the gap.
Not all hyperscalers are equal
The distinction that matters most within the group is between companies that can self-fund most of their spending and Oracle, which cannot. Unlike the other four hyperscalers, Oracle will have negative free cash flow until 2029, meaning its capital expenditures will exceed cash from operations, according to Bank of America. It has less capacity to take on more debt.
The market has noticed. The cost to insure Oracle's debt through credit default swaps has more than tripled since September 2025, according to MUFG. The other four hyperscalers carry credit ratings on the elite end of the investment-grade spectrum: Microsoft at AAA, Alphabet at AA+, Meta at AA-, and Amazon at AA-. Oracle sits at BBB, two downgrades from junk.
That spread in credit quality shows why the index-level story requires granularity. Five companies are entering the top ranks of the same index, but they bring different risk profiles. For the four with fortress balance sheets, bond issuance reflects capital structure optimization. For Oracle, it reflects necessity.
What it means for the index
U.S. corporate bond issuance is expected to increase substantially in 2026, with AI-related funding the biggest factor, according to Barclays. Overall U.S. corporate bond issuance is expected to reach $2.46 trillion in 2026, up 11.8% from $2.2 trillion in 2025. Net issuance should rise 30.2% to $945 billion. Passive bond funds that track investment-grade indexes will mechanically absorb more tech debt as these companies issue more.
Even after billions of issuance, most hyperscalers will carry leverage of 0.4 to 0.7 times, compared with an average of just under three times for the broader U.S. investment-grade market, according to M&G Investments. The credit quality, for now, is high. The concentration is the concern.
The investment-grade bond index was, until recently, a place where banks, industrials, and utilities dominated. It is becoming a place where a handful of tech companies spending hundreds of billions on AI infrastructure hold a growing share of the weight.
The borrowers have changed. The index reflects it. Whether the buyers of that index have updated their own understanding is a different question.