By the time a rating agency downgrades a borrower, the market has usually known for months. Spreads widened, the equity fell, the analysts published, and the downgrade arrives as confirmation rather than information. This is not a scandal and it is not really a failure — an agency rating a long-dated obligation is deliberately slower than a price that moves every day.
It would be an academic point except that a great deal of capital is contractually obliged to act on the rating rather than on the price.
The lag is priced in and the flows are not
Investment mandates, insurance capital rules and index inclusion criteria all reference ratings, because a rating is an external, auditable, contractible number and a spread is not. That is a reasonable thing to write into a mandate and it produces a peculiar result: a fund that has known a credit is deteriorating for six months may be unable to sell until an agency says so, and then may be obliged to sell immediately.
So the downgrade contains no new information and still moves an enormous amount of paper, because the constraint it releases is real even when the news is not.
The sharpest version is the boundary between investment grade and high yield. Crossing it removes a bond from indices that a large body of passive money tracks and from mandates that may not hold sub-investment-grade paper at all — so a single notch produces selling entirely disproportionate to the change in underlying risk. The term for the resulting issuer is well established, and so is the pattern of a bond trading down into the event and recovering afterwards, as forced sellers finish and discretionary buyers who never had the constraint step in.
This is going to matter more over the next few years than it has recently. As the maturity wall reaches the borrowers who could not refinance early, a cohort of issuers will refinance at coupons that visibly weaken their coverage, and the ratings will follow — with the mechanical selling arriving after the price already reflected it.
Where the flows actually land is the second question, and increasingly the answer is not the bonds. A downgrade forces a fund to reduce exposure, and the fastest way to reduce exposure to a credit-heavy basket is to transact in the wrapper, which is why the bond ETF became the market's liquidity story rather than the underlying issues.
For anyone not bound by a mandate, the practical read is that the rating is a schedule rather than a signal. It tells you roughly when a predictable body of capital will be obliged to transact, which is a different and considerably more useful thing than an opinion about the credit.
Topics marketscreditfixed income
