Amazon launched a record-breaking $40 billion bond sale Tuesday, triggering the busiest day ever for US corporate debt markets. The ecommerce giant is marketing 11 tranches of dollar debt to raise up to $30 billion, with an additional €10 billion planned in euro-denominated bonds. The move comes as Big Tech accelerates borrowing to fund massive AI infrastructure investments.

Nearly a dozen blue-chip companies rushed to issue debt Tuesday, reviving markets that had stalled since Middle East conflict erupted. Investment-grade issuance is expected to reach $60 billion, surpassing the 2013 record when Verizon sold $49 billion in bonds. Amazon's sale attracted over $86 billion in orders before noon, with the longest 50-year bond yielding 1.55 percentage points over US Treasuries.

Amazon's aggressive borrowing spree reflects pressure from investors concerned about outsized AI spending, particularly on unprofitable startups like Anthropic and OpenAI. The company spooked markets in February by announcing $200 billion in planned capital expenditure for 2025, more than rivals Google and Microsoft. CEO Andy Jassy defended the strategy, promising to 'invest aggressively' to lead in AI infrastructure. The bond sales underscore how tech giants are leveraging low rates to finance their AI ambitions, even as they face scrutiny over mounting debt levels.