AI Financing Drives Expansion of U.S. Dollar Investment-Grade Private Placements, Taking the Market Beyond Its Niche Status

Overview

The report examines how AI infrastructure and data center financing are reshaping the U.S. dollar investment-grade private placement bond market, sequentially analyzing the prevalence of issuance, index inclusion requirements, liquidity, and the spread premium relative to registered bonds. Its core conclusion is that although private placements' share of the overall outstanding market has not risen dramatically, issuance volume, industry composition, and registration-rights structures have changed significantly, while institutional demand has also strengthened.

Core views

The report first distinguishes between the two principal forms of private issuance. Rule 144A allows issuers to bypass the SEC registration process and sell bonds only to qualified institutional buyers in the U.S. market, thereby improving issuance efficiency and reducing underwriting costs; since mid-2014, 144A transactions have been reported through TRACE. Reg S allows issuers to sell bonds to qualified foreign institutional buyers in offshore transactions. Most current investment-grade private placements establish both 144A and Reg S ISINs and are issued simultaneously to both investor groups, so the report refers to the two collectively as private placement bonds. AI infrastructure capital expenditure is significantly amplifying private placement bond supply. More than $270 billion of private placement bonds have been issued year-to-date in 2026 in the U.S. dollar non-financial investment-grade market, already matching the full-year 2025 supply and putting 2026 on track for a new record. AI-related issuance rose from 3% of private placement supply in 2024 to 42% year-to-date in 2026; all 20 of the largest U.S. dollar investment-grade bond tranches over the past year were AI-related, and the five largest were all privately placed. Large AI transactions have also increased the average size of an individual new private placement from $1.1 billion two years ago to $1.5 billion in 2026. However, the frequent appearance of large deals does not mean that private placements' share of the overall investment-grade market has increased to the same extent. Since the end of the global financial crisis, private issuance as a share of primary-market supply has risen only moderately, though the increase has been more pronounced in recent years; in the secondary market, private placements' share of outstanding U.S. dollar non-financial investment-grade bonds has remained broadly stable at 15% to 20% over nearly 15 years. The truly notable change is in the internal composition: the traditional outstanding stock is concentrated mainly in utilities, oil and gas, and automobiles, whereas new supply over the past 12 months has been dominated by AI-related industries. Another structural change involves registration rights. In recent years, there has been a notable increase in investment-grade private placements issued without registration rights and intended to remain permanently in 144A form, partly due to extensive financing by special-purpose vehicles for AI infrastructure. The share of such issuance that is index-ineligible has generally increased in recent years, although the 2026 share is the lowest since 2022. The U.S. dollar high-yield bond market generally permits 144A and Reg S private placements to be included in indices, while major U.S. dollar investment-grade indices require private placements to carry registration rights, allowing the bonds to be exchanged later for SEC-registered bonds. Consequently, recently issued data center financing bonds structured as “144A-for-life” will remain outside the indices. The report estimates that approximately $2.4 trillion of U.S. dollar investment-grade bonds are currently index-ineligible due to the absence of registration rights, equivalent to 20% of the broader market; AI-related bonds currently account for only slightly more than 4% of this outstanding stock of index-ineligible private placements. In terms of liquidity, private placements can reach a smaller pool of qualified institutional buyers than the investor universe available to registered bonds, resulting in slower secondary-market trading. The data confirm this mechanism: turnover in U.S. dollar investment-grade private placements is about half that of registered bonds. Nevertheless, trading volumes for both types of bonds have risen over the past few years, and the report cites prior research showing no material difference in bid-ask spreads between registered and 144A bonds. This means that although private placements turn over more slowly, their actual transaction costs are very similar to those of registered bonds. The report further uses a regression model to estimate the spread premium of private placements relative to registered bonds while controlling for differences in ratings, payment priority, industry, and duration. Historically, private placements have provided an average of approximately 30 basis points of additional spread; this premium has continued to compress in recent years and is now closer to 15 basis points. The report therefore concludes that rising trading volumes and the narrowing overall premium reflect increasing institutional familiarity with and demand for this asset class. The TMT segment exhibits a different trend. This segment includes most AI-related issuers, and after its private placement premium narrowed for several consecutive years and briefly turned negative, it widened significantly over the past four months in tandem with accelerating AI-related supply. This indicates that greater overall market acceptance of private placements has not eliminated the impact of concentrated supply on relative pricing in specific industries. The difference in primary-market pricing is minimal. Over the past 12 months, the average new issue concession for U.S. dollar investment-grade private placements was 6 basis points, compared with 5 basis points for registered bonds. Overall, the investor base and turnover of private placements remain constrained, and the absence of registration rights also results in index ineligibility; however, the narrowing overall spread premium, rising trading volumes, and nearly identical new issue concessions support the report's view that this market is moving from a niche segment toward a mainstream institutional asset class.

Analysis framework

The report first explains the issuance mechanisms of 144A and Reg S, then uses historical issuance and outstanding-market shares to determine whether private placements have genuinely become more prevalent. It subsequently analyzes how registration rights determine index eligibility and compares liquidity using turnover, measured as trading volume relative to outstanding bonds, and bid-ask spreads. Finally, the report uses a regression model controlling for ratings, industry, payment priority, and duration to estimate the spread premium of private placements relative to registered bonds, examining the overall market separately from the TMT segment, where AI issuance is concentrated.

Methodology notes

• Fixed Income and Credit AnalysisSpread analysis

  Excess spread of private placement bonds relative to registered bonds

  The report compares the spreads of private placements with those of registered bonds to measure the compensation investors require for a smaller buyer universe and lower turnover, and examines how this compensation changes over time and in response to industry supply.

• Quantitative/Factor/Portfolio Theory

  Regression model controlling for bond characteristics

  The model controls for ratings, industry, payment priority, and duration to remove, as far as possible, spread differences caused by variations in bonds' fundamental characteristics, thereby estimating the spread premium attributable to the private issuance format itself.

• Industry/Sector Analysis FrameworkSupply-demand framework

  Changes in AI financing supply and institutional demand

  The report tracks the surge in issuance resulting from AI infrastructure financing while using changes in trading volumes and spread premiums to assess institutional demand and market acceptance, and explains why concentrated TMT supply corresponds to a localized widening of the premium.

• Fixed Income and Credit Analysis

  Liquidity comparison using turnover and bid-ask spreads

  The report measures trading activity using average daily trading volume as a percentage of outstanding bonds while also comparing bid-ask spreads, distinguishing between slower turnover and higher actual transaction costs.

Asset mapping & comparison

Structured mapping from thesis to named assets (strengths, weaknesses, peers, risks).

• U.S. Dollar Investment-Grade Private Placement Bonds (144A/Reg S)

  Financing for AI infrastructure and data center capital expenditure is driving growth in issuance volume and individual deal size, increasing this market's importance within the investment-grade credit ecosystem.

  Strengths

  The overall excess spread remains approximately 15 basis points; trading volumes have risen in recent years; bid-ask spreads are very similar to those of registered bonds; and the primary-market new issue concession is only 1 basis point higher than for registered bonds.

  Weaknesses

  The qualified institutional buyer universe is narrower, and turnover is approximately half that of registered bonds; bonds without registration rights cannot be included in major U.S. dollar investment-grade indices.

  Comparison

  Historically, private placements offered a premium of approximately 30 basis points relative to registered bonds, compared with approximately 15 basis points overall currently; new issue concessions over the past 12 months were 6 and 5 basis points, respectively.

  Risks

  Against the backdrop of accelerating supply, the spread premium on TMT and AI-related private placements has widened significantly over the past four months.

Key data

• Private placement issuance year-to-date in 2026More than $270 billionAlready equivalent to the full-year 2025 supply, with 2026 on track to set a record
• Share of AI-related issuance42%Year-to-date in 2026; only 3% in 2024
• Largest U.S. dollar investment-grade bond tranches over the past yearAll 20 were AI-relatedThe five largest were all privately placed
• Average size of an individual new private placement$1.5 billion$1.1 billion two years ago; large AI transactions increased the average size
• Private placement share of secondary-market bonds outstanding15% to 20%Broadly remained within this range over nearly 15 years
• U.S. dollar investment-grade bonds ineligible for indices due to the absence of registration rightsApproximately $2.4 trillionApproximately 20% of the broader U.S. dollar investment-grade market
• AI-related bonds as a share of outstanding index-ineligible private placementsSlightly more than 4%Currently still only a small portion of this outstanding market
• Relative turnover of private placement bondsApproximately half that of registered bondsReflects the narrower qualified buyer universe, although trading volumes for both types of bonds have risen in recent years
• Historical excess spread on private placement bondsApproximately 30 basis pointsRelative to registered bonds with comparable characteristics
• Current overall excess spread on private placement bondsApproximately 15 basis pointsSignificantly compressed from historical levels
• Change in TMT private placement bond premiumWidened significantly over the past four monthsIt had previously narrowed for several consecutive years and briefly turned negative
• New issue concession for private placement bonds6 basis pointsAverage over the past 12 months; 5 basis points for registered bonds

Impact & implications

The report believes that financing for AI capital expenditure is changing the issuance volume, industry composition, and registration-rights structure of the U.S. dollar investment-grade private placement bond market, but has not yet caused a dramatic increase in its overall share of outstanding bonds. Stronger institutional demand has brought the overall private placement spread premium and new issue concession closer to those of registered bonds, but the absence of registration rights still leads to index exclusion, while the narrower buyer universe also results in significantly lower turnover; meanwhile, concentrated TMT supply has caused localized relative spread widening.

Risks

• The qualified buyer universe for private placements is smaller than that of the registered bond market, and their turnover is approximately half that of registered bonds.
• “144A-for-life” bonds without registration rights cannot be included in major U.S. dollar investment-grade indices, and recently issued data center bonds of this type will remain outside the indices.
• Concentrated growth in AI-related supply has coincided with a significant widening of the TMT private placement bond spread premium over the past four months.