Chapter 23 Credit risk Options, Futures, and Other Derivatives, 8th Edition Copyright o John C Hull 2012
Chapter 23 Credit Risk Options, Futures, and Other Derivatives, 8th Edition, Copyright © John C. Hull 2012 1
Credit Ratings o In the s&P rating system, AAa is the best rating. After that comes AA, A, BBB, BB, B CCC. CC, and c e The corresponding Moody' s ratings are Aaa, Aaa. baa. ba. b caa ca and c e Bonds with ratings of BBB (or Baa) and above are considered to be investment grade Options, Futures, and Other Derivatives, 8th Edition Copyright@ John C. Hull 2012
Credit Ratings In the S&P rating system, AAA is the best rating. After that comes AA, A, BBB, BB, B, CCC, CC, and C The corresponding Moody’s ratings are Aaa, Aa, A, Baa, Ba, B,Caa, Ca, and C Bonds with ratings of BBB (or Baa) and above are considered to be “investment grade” Options, Futures, and Other Derivatives, 8th Edition, Copyright © John C. Hull 2012 2
Historical data Historical data provided by rating agencies are also used to estimate the probability of default Options, Futures, and Other Derivatives, 8th Edition Copyright@ John C. Hull 2012 3
Historical Data Historical data provided by rating agencies are also used to estimate the probability of default Options, Futures, and Other Derivatives, 8th Edition, Copyright © John C. Hull 2012 3
Cumulative Ave Default rates(%) (1970-2009, Moody's, Table 23. 1, page 522) 2345710 Aaa 00000.0120.0120.0370.1050.2450497 0.0220.0590.0910.1590.2340.3840.542 A 0.0510.1650.34105200.7171.1792046 0.17604940.91214041.92629964.851 Ba 1.1663.1865.5838.12310.39714.31819.964 4.5461042616.18821.25625.8953447344.377 Caa-C17.72329384386824609452.2865977171376 Options, Futures, and Other Derivatives, 8th Edition, Copyright o John C Hull 2012
Cumulative Ave Default Rates (%) (1970-2009, Moody’s, Table 23.1, page 522) Options, Futures, and Other Derivatives, 8th Edition, Copyright © John C. Hull 2012 4 1 2 3 4 5 7 10 Aaa 0.000 0.012 0.012 0.037 0.105 0.245 0.497 Aa 0.022 0.059 0.091 0.159 0.234 0.384 0.542 A 0.051 0.165 0.341 0.520 0.717 1.179 2.046 Baa 0.176 0.494 0.912 1.404 1.926 2.996 4.851 Ba 1.166 3.186 5.583 8.123 10.397 14.318 19.964 B 4.546 10.426 16.188 21.256 25.895 34.473 44.377 Caa-C 17.723 29.384 38.682 46.094 52.286 59.771 71.376
Interpretation o The table shows the probability of default for companies starting with a particular credit rating o a company with an initial credit rating of Baa has a probability of 0. 176% of defaulting by the end of the first year, 0.494% by the end of the second year, and So on Options, Futures, and Other Derivatives, 8th Edition Copyright@ John C. Hull 2012 5
Interpretation The table shows the probability of default for companies starting with a particular credit rating A company with an initial credit rating of Baa has a probability of 0.176% of defaulting by the end of the first year, 0.494% by the end of the second year, and so on Options, Futures, and Other Derivatives, 8th Edition, Copyright © John C. Hull 2012 5