Credit Rating Transition Matrix & Migration Risk Lab
Simulate multi-year credit rating migration, Markov transition powers (Pt), cumulative default probabilities, fallen angel risk, and portfolio MTM revaluation.
Position & Horizon Parameters
Migration & Default Analytics
Investment Grade (BBB)Migration Profile Analysis
Starting at BBB, the position has an 82.3% probability of remaining investment grade, with an 11.5% chance of transitioning to high-yield speculative status.
| Ending Rating Tier | Transition Prob (%) | Credit Spread | Expected Price ($) |
|---|
Cumulative Default Term Structure (1 to 10 Years)
| Rating Tier | 1 Year | 2 Years | 3 Years | 5 Years | 7 Years | 10 Years |
|---|
1-Year Baseline Transition Probability Matrix (P)
Empirical annual transition frequencies (row = starting rating, column = rating after 1 year). Diagonal elements indicate rating stability.
Credit Rating Migration & Markov Risk Quiz
Frequently Asked Questions
What is a credit rating transition matrix?
A credit rating transition matrix is a square probability table where row i represents an obligor's starting credit rating and column j represents the probability of migrating to rating j over a specified time horizon (typically one year). Default (D) represents an absorbing state with a 100% probability of remaining in default.
How are multi-year cumulative default probabilities calculated from transition matrices?
Assuming a discrete-time stationary Markov process, the t-year transition matrix P(t) is computed by multiplying the 1-year matrix by itself t times: P(t) = P^t. The entry in row i and column D represents the cumulative probability of defaulting within t years for a borrower starting at rating tier i.
What is fallen angel risk in corporate credit portfolios?
Fallen angel risk refers to the probability that a corporate bond rated BBB (the lowest investment-grade tier) gets downgraded to BB or lower (speculative grade / high yield). Such downgrades force institutional mandate selling by benchmark-constrained funds, causing steep price discounts and liquidity dry-ups.
How does credit rating migration impact bond mark-to-market valuations?
Under the CreditMetrics framework, each rating tier corresponds to an empirical market credit spread. When a bond is downgraded, its required spread widens, leading to an immediate mark-to-market capital loss approximately equal to: Delta V = -Modified Duration * Delta Spread. If the borrower defaults, the bond value drops to its recovery value (1 - LGD).