> ## Documentation Index
> Fetch the complete documentation index at: https://docs.activeviam.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Tranche

The **Tranche** (Underlying) object describes the tranche.  A tranche is specific to an underlying asset pool.

| Field                | Key | Description                                                                     |
| -------------------- | --- | ------------------------------------------------------------------------------- |
| As-of Date           | Y   | Timestamp (at close of business) for the data (T-1)                             |
| Tranche (Underlying) | Y   | Name of the tranche                                                             |
| Risk Class           | Y   | “DRC Sec non-CTP”                                                               |
| Bucket               |     | “Corporates” or asset class and region                                          |
| Seniority            |     | “senior” or not, for calculating the SEC-ERBA risk-weight                       |
| Rating               |     | Credit rating of the tranche                                                    |
| Rating Type          |     | The rating type used alongside the rating to determine the SEC-ERBA risk-weight |
| Region               |     | The region used to determine the bucket                                         |
| Asset Class          |     | The asset class used to determine the bucket                                    |
| Attachment Point     |     | Attachment point of the tranche within the pool                                 |
| Detachment Point     |     | Detachment point of the tranche within the pool                                 |
| Risk Weight          |     | Optional override of the obligor’s risk-weight                                  |