US Tech Giants’ AI Bond Boom Could Push Up European Borrowing Costs, ECB Warns

Frankfurt: Europe could face higher borrowing costs as US technology giants increasingly turn to European bond markets to fund their massive artificial intelligence infrastructure investments, according to economists at the European Central Bank.

The ECB analysts said the rapid expansion of AI data centres is creating enormous financing requirements for companies such as Alphabet, Amazon, Meta, Microsoft and Oracle. Increasing amounts of that funding are being raised through bonds denominated in euros.

The five technology companies have nearly doubled their share of euro-denominated debt issued by non-financial US companies between 2025 and 2026. Together, they now have around €40 billion of outstanding euro-denominated bonds, accounting for just under 10% of the euro bond market for non-financial corporate issuers.

AI Investment Creates Massive Funding Needs

The ECB's warning comes as the world's largest technology companies race to expand computing infrastructure needed for artificial intelligence.

These companies, often described as hyperscalers, are investing heavily in data centres, servers, electricity infrastructure and other equipment required to support rapidly growing AI services.

The scale of investment could become significantly larger. The ECB analysts estimate that hyperscalers could require more than $1 trillion in capital expenditure by 2028.

Such borrowing could have consequences beyond the technology sector.

As large US companies issue more bonds, they may compete directly with European corporations and governments for the same pool of investors. If demand for European sovereign debt weakens, governments may have to offer higher yields to attract buyers.

No Major Spillover Yet

The ECB economists stressed that there is currently no clear evidence of major spillover effects from US technology companies' bond issuance into the eurozone's sovereign debt market.

The relatively limited scale of technology-sector borrowing so far, combined with the resilience of European government bond markets, has helped prevent a significant impact.

However, the analysts cautioned that the situation could change as AI investment accelerates.

A sustained increase in technology-sector borrowing could eventually alter the structure of European bond markets and force companies, governments, banks and investors to adjust their strategies.

Tech Bonds Could Compete With Government Debt

The ECB identified several possible channels through which the technology borrowing boom could affect European government financing.

Investors may choose to shift money away from traditionally safer government bonds and into debt issued by major technology companies if the latter offers attractive returns.

The growing presence of technology companies in major bond indexes could also trigger automatic portfolio adjustments, potentially reducing investors' exposure to sovereign debt.

Greater competition for capital could then push European issuers to offer higher yields.

That would increase borrowing costs for governments at a time when eurozone bond yields are already elevated.

European Bond Yields Under Pressure

The ECB's warning arrives as European debt markets are experiencing renewed pressure.

Germany's 10-year Bund yield, a key benchmark for eurozone borrowing costs, climbed to around 3.32% on Monday, reaching its highest level since 2011.

The rise was partly linked to renewed tensions between the United States and Iran, which have increased concerns about energy prices and a possible resurgence in inflation. Markets are also reassessing the outlook for European interest rates.

Higher government yields combined with rising corporate borrowing could make financing more expensive across the European economy.

The ECB analysts therefore described the current AI financing trend as potentially only the beginning of a much larger transformation.

If hyperscalers continue raising enormous sums through bond markets to fund AI expansion, the resulting competition for capital could reshape European debt markets and influence financing costs across the region.