Explanation

In credit rating methodologies, rating agencies apply notching adjustments to reflect differences in recovery prospects between different classes of debt within the same issuer. The key points are:

1. Notching for subordinated debt: Subordinated debt typically receives a lower rating than senior unsecured debt of the same issuer due to its lower priority in the capital structure and poorer recovery prospects in default.

2. Speculative grade vs. investment grade differences:

   • For investment grade issuers, the probability of default is relatively low, so the notching adjustment for subordination tends to be larger (typically 1-2 notches) because the focus is more on recovery prospects.
   • For speculative grade issuers, the probability of default is higher, and recovery rates for all debt classes tend to be lower. Therefore, the notching adjustment for subordination is typically smaller (often 0-1 notches) because the primary concern is default probability rather than recovery differentials.

3. Rationale: When an issuer is already speculative grade, the incremental risk from subordination is less significant compared to the overall default risk. The market already prices in substantial default risk, so the additional penalty for subordination is smaller.

4. CFA curriculum reference: This concept is covered in the Fixed Income section of the CFA curriculum, specifically in discussions about credit rating methodologies and notching practices.

Therefore, the correct answer is A: smaller than that applied to the subordinated debt rating of investment grade issuers.