> ## 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.

# Risk weight

The **[Risk Weights](../../../../../../../cube/drc-sec-non-ctp-jtd-weightings)** are defined in [MAR22.34](https://www.bis.org/basel_framework/chapter/MAR/22.htm?inforce=20230101\&published=20200327#paragraph_MAR_22_20230101_22_34).
They may be provided in the input files for each tranche.
Otherwise the SEC-ERBA risk weights are determined for the tranche as specified in [CRE42](https://www.bis.org/basel_framework/chapter/CRE/42.htm?inforce=20230101\&published=20230101).

The risk weights are looked up from the [SEC-ERBA risk weights](../../configuration-core/sec-erba-risk-weights) store.
They are looked up by **Rating**, **Rating Type** and **Seniority**.
For non-senior tranches the  **Attachment Point** and **Detachment Point** are used to determine the tranche thickness.