(a) General requirement. At least weekly, a national bank or Federal savings association must use the same internal model(s) used to calculate its VaR-based measure to calculate a stressed VaR-based measure.

(b) Quantitative requirements for stressed VaR-based measure.

(1) A national bank or Federal savings association must calculate a stressed VaR-based measure for its covered positions using the same model(s) used to calculate the VaR-based measure, subject to the same confidence level and holding period applicable to the VaR-based measure under §3.205, but with model inputs calibrated to historical data from a continuous 12-month period that reflects a period of significant financial stress appropriate to the national bank's or Federal savings association's current portfolio.

(2) The stressed VaR-based measure must be calculated at least weekly and be no less than the national bank's or Federal savings association's VaR-based measure.

(3) A national bank or Federal savings association must have policies and procedures that describe how it determines the period of significant financial stress used to calculate the national bank's or Federal savings association's stressed VaR-based measure under this section and must be able to provide empirical support for the period used. The national bank or Federal savings association must obtain the prior approval of the OCC for, and notify the OCC if the national bank or Federal savings association makes any material changes to, these policies and procedures. The policies and procedures must address:

(i) How the national bank or Federal savings association links the period of significant financial stress used to calculate the stressed VaR-based measure to the composition and directional bias of its current portfolio; and

(ii) The national bank's or Federal savings association's process for selecting, reviewing, and updating the period of significant financial stress used to calculate the stressed VaR-based measure and for monitoring the appropriateness of the period to the national bank's or Federal savings association's current portfolio.

(4) Nothing in this section prevents the OCC from requiring a national bank or Federal savings association to use a different period of significant financial stress in the calculation of the stressed VaR-based measure.