Artificial intelligence (AI) is usually seen as a stock market story. But building the data centres, chips, networks and power infrastructure behind it needs huge amounts of money. Increasingly, that money is coming from bond markets.
This article isn’t personal advice. Investments rise and fall in value, so you could get back less than you invest. If you’re not sure whether an investment is right for you, ask for financial advice.
Why are hyperscalers issuing more bonds?
The largest cloud-computing companies, often called hyperscalers, include Alphabet, Amazon, Meta and Microsoft. They’ve traditionally generated enough cash themselves to fund the investments they’ve wanted to make. But the race to develop AI is changing that.
Spending has accelerated as companies compete for computing capacity and are building infrastructure ahead of demand. Most hyperscalers still have strong balance sheets and high credit ratings, so they can borrow relatively cheaply. But the shift is important.
How could this change bond indices?
Many corporate bond indices are weighted by the market value of a company’s bonds. Put simply, the more a company borrows, the bigger its potential weight in an index. That’s different from a share index, where a rising weight will usually reflect a more valuable company.
This matters for passive investors. As more hyperscaler bonds enter indices, tracker funds have no choice but to buy those bonds, increasing their exposure to those companies.
The maturity of the new debt matters too. Long-dated issuance can increase an index’s sensitivity to changes in interest rates – known as duration. This can make bond prices more volatile when interest rates move.
Hyperscalers have issued $48bn worth of bonds in European currencies like the Euro, Pound Sterling and Swiss Franc so far this year, more than triple the amount in 2025. This means that they account for 3% of investment-grade bonds issued in Euros so far in 2026, and 10% of those issued in Sterling.
When it comes to bonds issued in US Dollars, hyperscaler bonds account for 8% of bonds issued so far in 2026.
Amazon’s weight in the US investment-grade bond market has risen sharply as the company has increased its borrowing to fund investment.
These are big numbers.
In September 2026, hyperscaler bonds accounted for around £3 in every £100 invested in US investment-grade bond indices. It was around £1 for each of the Sterling and Euro markets too. These numbers are expected to continue increasing.
What does it mean for bond markets?
More supply can create challenges. And strong companies don’t automatically make attractive bond investments.
If markets have to absorb a steady stream of new debt, credit spreads – the extra yield companies pay on their debt compared with governments – could get bigger. And if investors become less confident that AI spending will produce adequate returns, they could demand more compensation. This doesn’t just impact hyperscaler bonds either. With a bigger amount of overall supply, there’s potential for prices of bonds from other companies to fall as well.
The impact goes beyond Big Tech.
AI needs electricity generation, grid connections, fibre networks, cooling systems and specialist property. Utilities, data-centre operators and infrastructure companies are borrowing too. Some funding is also appearing in private credit, leases and asset-backed securities. Investors could therefore have indirect exposure to hyperscaler investment spending and the AI theme across several fixed income sectors and funds.
What are the risks?
The biggest question is whether the investments these bonds are funding produce enough future cash flow to make it worthwhile. Demand could disappoint, competition could increase, or prices could fall. At the same time, higher debt, weaker free cash flow and continued shareholder payouts could put pressure on credit ratings. That would potentially push down the value of bonds, with investors requiring a higher rate of return for a higher level of risk.
What should investors consider?
Start by checking what a fund actually owns. Its biggest issuer and sector positions can show how much hyperscaler risk is already in the fund.
Consider the trade-off between active and passive funds. Index funds offer broad, low-cost exposure, but they have to invest in all bonds in the index they’re tracking. Active managers can limit concentrations and choose which bonds to buy, although there’s no guarantee that’ll improve returns.
If bonds are held for diversification as part of a balanced portfolio, investors should consider their overall exposure to AI across asset classes. It’s likely that investments in shares will include at least some hyperscalers.
So, if there is a wider problem with AI development, there’s potential for both the shares and bonds in a portfolio to sell off at the same time. That would make the diversification expected of the bond part of the portfolio less effective.
At current levels this is unlikely to be a major concern. But if the amount of new bonds coming to market from hyperscalers continues, then this becomes a bigger risk and something investors will need to monitor.