The US convertible bond market just posted a number that would have seemed absurd three years ago. Companies listed in the US have raised $131 billion in convertible debt year-to-date through early September 2026, according to Bloomberg data, blowing past the previous annual record set just two years prior.
The culprit, or hero depending on your portfolio, is artificial intelligence. Roughly half of the convertible bonds issued this year are tied to AI initiatives, as companies race to build the data centers, buy the chips, and deploy the infrastructure needed to stay relevant in a market that punishes anyone who falls behind.
The deals driving the boom
August alone accounted for $25 billion in convertible bond issuance, a staggering single-month haul that underscores how urgent the capital needs have become.
The roster of borrowers reads like an AI supply chain directory. CoreWeave tapped the market for $4 billion, Oracle raised $5 billion, ON Semiconductor issued $1.3 billion in zero-coupon convertibles, and Ciena Corp followed with a $2.9 billion zero-coupon deal of its own.
Zero-coupon convertibles, bonds that pay no interest at all, are on track for a record year globally. According to Dealogic, these deals accounted for 41% of US convertible issuance in 2026.
Why convertibles, and why now
For the companies involved, the math is straightforward. AI capital expenditures are growing faster than internal cash flows can fund them. JPMorgan estimates that AI-related high-grade bond issuance has reached $266 billion year-to-date in 2026, and projects that cumulative financing needs for AI capital expenditures will hit $2.1 trillion over the next five years.
The previous full-year record was set in 2025, when US convertible bond issuance exceeded $120 billion. The initial months of 2026 showed activity running at more than double the prior year’s pace, which explains how the market blew past that mark before autumn even arrived.