A surge in corporate spending on AI, capex, and M&A can boost stock prices. However, this same activity often requires issuing large amounts of new debt, increasing supply and causing credit spreads to widen, leading to underperformance versus equities.

The US corporate market is 75% financed by capital markets, while Europe's is ~80% bank-financed. This structural inversion means Europe is undergoing a long-term, multi-decade shift toward institutional lending, creating a sustained tailwind for private credit growth that is far from mature.

While the US private credit market is saturated, Europe's middle-market offers higher spreads (north of 600 basis points) and lower leverage. This opportunity is most pronounced in non-sponsor deals, a segment where large banks and public markets are less active, creating a lucrative niche.

Morgan Stanley predicts the AI investment cycle, plus M&A and capex, will drive a 60% surge in U.S. investment-grade bond issuance in 2026. This massive supply increase is expected to push U.S. credit spreads wider, even if the underlying economy remains healthy and demand is strong.

The massive ~$1.5 trillion in debt financing required for AI infrastructure will create a supply glut in the investment-grade (IG) bond market. This technical pressure, despite solid company fundamentals, makes IG bonds less attractive. High-yield (HY) bonds are favored as they don't face this supply headwind and default rates are expected to fall.

The sheer volume of debt needed to fund AI infrastructure will likely widen spreads in investment-grade bonds and related ABS. This supply pressure creates an opportunity for outperformance in insulated sectors like US high-yield and agency mortgage-backed securities.

Despite forecasting a massive surge in bond issuance to fund AI and M&A, Morgan Stanley expects credit spreads to widen only modestly. This is because high-quality, highly-rated companies will lead the issuance, and continued demand from yield-focused buyers should help anchor spreads.

A significant shift in corporate finance strategy has occurred: companies no longer universally strive for an investment-grade (IG) rating. Many firms, including 'fallen angels' downgraded from IG, are content to operate with a high-yield rating, finding the higher borrowing costs acceptable for their business models.

A surge in investment-grade bond issuance to fund AI capital expenditures will insulate the high-yield market. This technical factor is expected to drive high-yield bond outperformance versus higher-quality corporate bonds, which will face supply pressure.