Three Firms Rate the World's Debt. The Borrower Pays Them.

On 16 May 2025 Moody's cut the United States federal government from Aaa to Aa1, and with that the last of the three big agencies agreed the American government was no longer a flawless credit. The Treasury did not miss a payment. Nothing about the bonds changed between Thursday and Friday. What changed was one company's opinion, published as a letter, and the letter moved yields, ran on front pages across three continents, and sent a category of investors back to their rulebooks. Three firms get to do that. And the governments and companies they grade are the ones who pay to have it done.

1. Three firms grade 95% of the debt

S&P Global and Moody's take roughly 40% of the ratings market each, Fitch takes most of what is left, and together the three cover about 95% of the rated debt on the planet. This is not an accident of competition. The Securities and Exchange Commission blessed it in 1975 by inventing a label, the "nationally recognised statistical rating organisation", then wiring that label into its own rules. Once a rating from an approved firm was something regulators required rather than merely trusted, the approved firms had a moat the market could not dig around.

What the letter actually claims is narrower than it looks. A rating is not a price target and not a buy recommendation. It is one firm's estimate of how likely a borrower is to miss a payment, compressed onto a scale that runs from AAA at the top down to D for a borrower already in default. The scale wears the costume of a measurement. Read the agencies' own disclaimers and you find the truth: a rating is described as an opinion, protected as free speech, the same legal category as a newspaper column. It carries the authority of a thermometer and the accountability of an op-ed. The entire system runs on treating it as the former.

2. The borrower writes the cheque

Here is the part that should give anyone pause. Until the early 1970s, investors bought the ratings. You subscribed, you got the research, the reader paid for the opinion he was relying on. Then the agencies flipped the model. Today the company or government being rated is the one who pays for its own rating. The referee is on the payroll of one of the teams.

The tidy justification is that photocopiers made a subscription too easy to share, so the revenue had to move. The consequence is harder to tidy away. An issuer can quietly sound out an agency, get a sense of the likely grade, and take its business to a competitor if it does not like the preview. The practice has a name, ratings shopping, and nobody in it has to be corrupt for the incentive to bend the outcome. When the customer paying your invoice is also the subject of your verdict, and can walk if the verdict stings, the pull is structural. It works on honest people too.

3. AAA on subprime, then a $1.375 billion cheque

We already ran the experiment on what that pull produces. In the years before 2008 the agencies stamped AAA, the grade reserved for the safest credits on earth, onto mortgage bonds assembled from loans that were nothing of the kind. When the loans went bad the agencies downgraded thousands of those securities in a rush, turning assets banks held because of the rating into junk, and detonating the balance sheets built on top of them. In 2015 S&P paid $1.375 billion to settle claims by the US Justice Department and nineteen states that it had knowingly inflated those grades to win business. It admitted no wrongdoing. Moody's later settled on comparable terms.

"A rating is an opinion until a rulebook turns it into an order. Then it is the most powerful sentence in finance that nobody had to vote on."

And then the model survived. The 2010 Dodd-Frank Act ordered regulators to strip references to ratings out of their own rules, on the theory that if the law stopped requiring a grade, the agencies would lose the franchise that made them untouchable. Fifteen years on, most of those references are still there. The scandal cost the agencies a fine and cost nobody the business. Why would a system this profitable reform itself when the people it failed had no exit?

4. A downgrade forces selling even when no one is surprised

The reason the letter has teeth has almost nothing to do with whether the letter is right. Ratings are welded into the machinery of finance. Bank capital rules under Basel set how much capital a bank must hold against a bond according to its grade. Insurance regulators, money-market fund rules, central-bank collateral frameworks and thousands of private investment mandates all key off the same few letters. So a downgrade is not an opinion you are free to take or leave. Cross the wrong threshold and holders are forced to act whatever they personally believe. A bond that slips from investment grade (BBB) to junk (BB) becomes a "fallen angel", and every fund permitted to hold only investment grade has to sell it, into a market where everyone else is selling for the identical reason on the identical morning.

Then look at France, which shows the other edge of the same blade. Fitch cut France to A+ in September 2025 and S&P followed in October, the lowest grades the country had carried on record. And yet, across large parts of European bank regulation, French government debt kept much of its privileged treatment, because the rules sort ratings into broad buckets and France had not fallen out of its bucket. The downgrade bruised the headlines more than it moved a single capital charge. That is the uncomfortable part. The same letter is a fire alarm in one rulebook and a shrug in another, and the borrower funding the agency is, in effect, betting on which rulebook is reading. Who decided a private opinion should be able to force a sale at all?

The takeaway

When an agency downgrades a government or a company, the reflex is to argue about whether they got it right. The more useful question is who is now required to act on the verdict, and who paid to have it written. The rating is an opinion. The forced selling it can trigger is not. A system that lets the graded party pick up the tab has already been caught getting the grade spectacularly wrong, paid for it in cash, admitted nothing, and kept the franchise intact. The open question is not whether the agencies are accurate. It is what it would actually take for one of them to lose the licence.