Global corporate bond issuance reached $2.8 trillion in the first half of 2026, surpassing the previous record set in H1 2021 by $340 billion. AI infrastructure companies alone accounted for $420 billion of that total, a 280% increase from the same period last year. The demand came not from speculative tech plays but from capital-intensive data center operators, semiconductor fabs, and power utility consortia financing multi-decade build-outs.

Investment-grade issuance rose 34% year-over-year, while high-yield volume climbed 18%, a divergence that reflects institutional caution layered over structural appetite. The average maturity on AI-linked infraco bonds stretched to 12.4 years, versus 7.2 years for non-AI corporate debt, signaling that investors are pricing in long payback cycles and treating these instruments as quasi-sovereign infrastructure exposure. Spreads on AI-backed IG paper compressed 22 basis points in Q2 alone, even as Federal Reserve policy remained restrictive. That pricing disconnect matters: it suggests that capital is treating AI build-out as a decoupled asset class, insulated from traditional cyclical risk.

The second-order effect is already visible in credit ratings activity. Moody's reported a 41% increase in new issue ratings volume in Q2, with structured finance and infrastructure debt driving the bulk of incremental revenue. The firm's full-year guidance, released July 18, anticipated sustained issuance strength through year-end, contingent on spreads holding below 150 basis points for IG tech. That threshold has held for 11 consecutive weeks. Meanwhile, traditional refinancing activity—corporate debt maturing in 2027-2028—has been crowded out of primary markets. Companies in non-AI sectors are paying 30-45 basis points more than they would have in a normalized issuance environment, effectively subsidizing the AI infraco build. The distortion is acute in the $1.2 trillion of corporate maturities coming due in 2027: issuers now face a choice between refinancing at elevated spreads or drawing on revolvers, compressing liquidity buffers.

Operators should watch three specific markers. First, whether the $140 billion pipeline of AI-linked bond issuance slated for Q3 prices at spreads tighter than 90 basis points over Treasuries; sustained compression there would confirm that capital is treating this infrastructure as perpetual. Second, whether high-yield issuance volume drops below $80 billion in Q3, signaling that non-IG borrowers are being priced out entirely. Third, monitor Moody's October earnings call for any commentary on rating downgrades in sectors competing for capital against AI infraco; early warnings would appear in discretionary industrials and commercial real estate.

The fact that institutional allocators are willing to lock capital into 12-year paper at compressed spreads, while the Fed holds overnight rates at 5.25%, tells you everything about where conviction lies. The question is not whether the AI build continues. The question is who gets starved when the primary market stays this tilted.