Editor’s note: This is general educational information about how credit ratings work in United States markets and what a downgrade does and does not set in motion. It is not investment advice. Everything below is drawn from the official documents listed at the end.
Analysis: the downgrade is usually the last event, not the first
The most useful correction in the official record is about sequence. The monitoring group’s view was that rating actions, including outlook changes, watch placements and the downgrade itself, are lagging indicators of the cost of debt capital, and that most of the credit spread widening for downgraded issuers occurs before the downgrade. Prices move as the conditions that eventually force the agency’s hand become visible in filings, order books and funding markets. A reader who treats the downgrade as the shock is reading the last page first.
That framing has a limit the staff drew themselves. They accepted that a move from investment grade to below investment grade could have a significant effect on the cost of debt capital, precisely because that boundary is where the contracts and mandates cluster. The generalisation about lagging indicators applies to the smooth part of the scale. The discontinuity is where mechanical selling, collateral calls and capital charges arrive at once, which is why the concentration of issuers just above the line is a market structure question rather than a curiosity.
The regulatory direction of travel is worth watching for the same reason. Section 939A(b) of the Dodd-Frank Act required the Commission to strip credit rating references from its own regulations and substitute alternative standards of creditworthiness. The Commission did that for Regulation M in a final rule adopted as Release No. 34-97657, published in the Federal Register on June 20, 2023 and effective on August 21, 2023. The old investment grade exception, which the Commission had treated as a proxy for the likelihood of manipulation risk, was replaced by an exception based on an issuer’s probability of default derived from a structural credit risk model, with a parallel record preservation requirement for broker-dealers who rely on it. The Commission’s stated concern was that referencing ratings in its rules may encourage undue reliance on them, and that ratings are potentially imprecise and often lagging.
The practical consequence is that the rating threshold has been leaving the public rulebook while remaining embedded in private documents that no regulator publishes. Fund mandates, credit agreements, receivables facilities and index construction rules are all negotiated or set commercially. A careful reader watching a specific issuer therefore learns more from the covenant and collateral language in its own filings, and from the composition of its lender and bondholder base, than from the letter grade that a downgrade changes.
What the documents say
A rating change is an opinion changing, not a business changing. Nothing is produced, sold or written off on the day an agency moves an issuer from the lowest investment grade rung into speculative grade. What moves is a reference point that other contracts, mandates and rules were built on top of. The Securities and Exchange Commission has spent years documenting exactly how much of that plumbing exists, how it behaves under stress, and how much of it the agency has since removed from its own rulebook.
What the rating is, and what the SEC says it is not
The SEC’s Office of Investor Education and Advocacy and Office of Credit Ratings describe a credit rating as an assessment of an entity’s ability to pay its financial obligations. Ratings apply to bonds, notes and other debt instruments, including certain asset-backed securities, and to companies and governments themselves. They do not apply to common stock. The scales run from a top grade of AAA down to D, which indicates default, and the agencies draw the investment grade line between the BBB and BB categories, so a rating of BBB-minus or higher is investment grade and anything below it is not.
The same bulletin is unusually direct about the limits. A rating does not reflect market or liquidity risk. It does not consider the price an investor paid or the price at which a security might be sold. It is not a guarantee of repayment, and the bulletin notes that instruments rated at the top of the scale sometimes default. Ratings are described as a prediction of how an obligor may behave in the future, built on one agency’s models, assumptions and expectations, and capable of changing at any time and at any rating level without warning. Some agencies publish outlooks and watch listings to flag a possible revision, but those alerts do not precede every rating action.
Who gets to issue these opinions in the United States is a matter of federal registration. The SEC’s Office of Credit Ratings examines and monitors the agencies registered as nationally recognized statistical rating organizations, or NRSROs, and its published register shows how narrow and how stable that group is. Fitch Ratings, Moody’s Investors Service and DBRS all trace their registration orders to Sept. 24, 2007, the year the registration regime came into force. Additions since then have been occasional rather than routine: Japan Credit Rating Agency and Kroll sit alongside insurance specialists such as A.M. Best and Demotech, and the most recent entrant, Clasificadora de Riesgo Pacific Credit Rating, was registered by an order dated January 5, 2026.
Where the automatic consequences actually live
The clearest official account of what a downgrade mechanically triggers came from the SEC’s COVID-19 Market Monitoring Group, an internal senior-level group announced on April 24, 2020, which published its observations on ratings, procyclicality and financial stability on July 15, 2020. Its finding on collateral is the concrete one. In receivables financing and similar arrangements where the reference collateral pool carries ratings, the staff wrote, there are usually contractual provisions to post additional or substitute collateral if posted collateral no longer maintains a specified rating, so that the borrowing base and the advance rate survive the change. The downgrade does not persuade anyone to demand more collateral. The document already said so.
The staff also set out the indirect channels in bilateral, secured financing: a downgrade of a corporate entity matters where that entity has servicing obligations to a financing trust, or acts as a swap counterparty to it, or where the financing provider’s confidence in the entity’s access to unsecured funding is part of the deal’s logic. On top of that, market participants in bilateral settings commonly impose rating-style financial criteria that are not mechanically linked to any agency’s letter but are likely to mimic ratings outcomes. The effect described is increased financing costs, reduced access, or liquidity pressure on the borrower.
The second channel is the composition of the investor base. The staff described observable segmentation of the credit universe between investment grade and non-investment grade credits, and observable concentration of credit around the line between them. They attributed that shape to several forces at once: recognition of the historical default-rate gap between the highest non-investment grade and lowest investment grade ratings, a long stretch of accommodative monetary policy that pushed investors to reach for yield inside their mandates, regulatory capital requirements that pushed lower-rated credit off the balance sheets of banks and insurers, and investment guidelines and index investing that build the segregation in directly. Balance sheet optimisation by borrowers aiming at the low investment grade range, they wrote, may have significantly contributed to the concentration in and around the BBB-/Baa3 categories.
The staff also pushed back on treating fund flows as the whole story. Registered investment companies, a category covering money market funds, other mutual funds and exchange-traded funds, account for roughly 21% of the United States and foreign corporate bonds market, 14% of the government agency securities market, 29% of the municipal securities market and 25% of the commercial paper market. Insurance companies and pension funds hold much of the rest, and their reactions to a rating action are far less visible in public data.
Congress limited what the SEC can do about the opinion itself
Under the Exchange Act provision codified at 15 U.S.C. 78o-7, an applicant for NRSRO registration must file ratings performance measurement statistics over short, medium and long-term periods, the procedures and methodologies it uses to determine ratings, and its policies on conflicts of interest and the misuse of material non-public information. Certain applicants must supply certifications from qualified institutional buyers stating that the buyer has used the applicant’s ratings for at least the 3 years immediately preceding the certification. The Commission can revoke a registration for a class of securities where an agency has failed over a sustained period to produce accurate ratings, and an agency may withdraw voluntarily by written notice.
What the statute does not permit is supervision of the opinion. As the monitoring group put it, “Congress explicitly prohibited the SEC and the states from regulating the substance of credit ratings” or the procedures and methodologies by which they are determined, a limit that sits in Exchange Act Section 15E©(2). Oversight therefore runs through process: agencies must maintain an internal control structure governing adherence to their own methodologies, and SEC staff examine whether they follow it. The Office of Credit Ratings published its most recent staff report on NRSROs on April 24, 2026.
