# 12 CFR § 3.211 - Simplified supervisory formula approach (SSFA).

§ 3.211 Simplified supervisory formula approach (SSFA).

(a) General requirements. To use the SSFA to determine the specific risk-weighting factor for a securitization position, a national bank or Federal savings association must have data that enables it to assign accurately the parameters described in paragraph (b) of this section. Data used to assign the parameters described in paragraph (b) of this section must be the most currently available data; if the contracts governing the underlying exposures of the securitization require payments on a monthly or quarterly basis, the data used to assign the parameters described in paragraph (b) of this section must be no more than 91 calendar days old. A national bank or Federal savings association that does not have the appropriate data to assign the parameters described in paragraph (b) of this section must assign a specific risk-weighting factor of 100 percent to the position.

(b) SSFA parameters. To calculate the specific risk-weighting factor for a securitization position using the SSFA, a national bank or Federal savings association must have accurate information on the five inputs to the SSFA calculation described in paragraphs (b)(1) through (b)(5) of this section.

(1) KG is the weighted-average (with unpaid principal used as the weight for each exposure) total capital requirement of the underlying exposures calculated using subpart D. KG is expressed as a decimal value between zero and one (that is, an average risk weight of 100 percent represents a value of KG equal to 0.08).

(2) Parameter W is expressed as a decimal value between zero and one. Parameter W is the ratio of the sum of the dollar amounts of any underlying exposures of the securitization that meet any of the criteria as set forth in paragraphs (b)(2)(i) through (vi) of this section to the balance, measured in dollars, of underlying exposures:

(i) Ninety days or more past due;

(ii) Subject to a bankruptcy or insolvency proceeding;

(iii) In the process of foreclosure;

(iv) Held as real estate owned;

(v) Has contractually deferred payments for 90 days or more, other than principal or interest payments deferred on:

(A) Federally-guaranteed student loans, in accordance with the terms of those guarantee programs; or

(B) Consumer loans, including non-federally-guaranteed student loans, provided that such payments are deferred pursuant to provisions included in the contract at the time funds are disbursed that provide for period(s) of deferral that are not initiated based on changes in the creditworthiness of the borrower; or

(vi) Is in default.

(3) Parameter A is the attachment point for the position, which represents the threshold at which credit losses will first be allocated to the position. Except as provided in § 3.210(b)(2)(vii)(D) for nth-to-default credit derivatives, parameter A equals the ratio of the current dollar amount of underlying exposures that are subordinated to the position of the national bank or Federal savings association to the current dollar amount of underlying exposures. Any reserve account funded by the accumulated cash flows from the underlying exposures that is subordinated to the position that contains the national bank's or Federal savings association's securitization exposure may be included in the calculation of parameter A to the extent that cash is present in the account. Parameter A is expressed as a decimal value between zero and one.

(4) Parameter D is the detachment point for the position, which represents the threshold at which credit losses of principal allocated to the position would result in a total loss of principal. Except as provided in § 3.210(b)(2)(vii)(D) for nth-to-default credit derivatives, parameter D equals parameter A plus the ratio of the current dollar amount of the securitization positions that are pari passu with the position (that is, have equal seniority with respect to credit risk) to the current dollar amount of the underlying exposures. Parameter D is expressed as a decimal value between zero and one.

(5) A supervisory calibration parameter, p, is equal to 0.5 for securitization positions that are not resecuritization positions and equal to 1.5 for resecuritization positions.

(c) Mechanics of the SSFA. KG and W are used to calculate KA, the augmented value of KG, which reflects the observed credit quality of the underlying exposures. KA is defined in paragraph (d) of this section. The values of parameters A and D, relative to KA determine the specific risk-weighting factor assigned to a position as described in this paragraph (c) and paragraph (d) of this section. The specific risk-weighting factor assigned to a securitization position, or portion of a position, as appropriate, is the larger of the specific risk-weighting factor determined in accordance with this paragraph (c), paragraph (d) of this section, and a specific risk-weighting factor of 1.6 percent.

(1) When the detachment point, parameter D, for a securitization position is less than or equal to KA, the position must be assigned a specific risk-weighting factor of 100 percent.

(2) When the attachment point, parameter A, for a securitization position is greater than or equal to KA, the national bank or Federal savings association must calculate the specific risk-weighting factor in accordance with paragraph (d) of this section.

(3) When A is less than KA and D is greater than KA, the specific risk-weighting factor is a weighted-average of 1.00 and KSSFA calculated under paragraphs (c)(3)(i) and (c)(3)(ii) of this section. For the purpose of this calculation:

(i) The weight assigned to 1.00 equals

$\begin{array}{c}\text{(ii) The weight assigned to}{\phantom{\rule{0ex}{0ex}}K}_{\mathrm{SSFA}}\phantom{\rule{0ex}{0ex}}\text{equals}\phantom{\rule{0ex}{0ex}}\frac{D-{K}_{A}}{D-A}.\phantom{\rule{0ex}{0ex}}\phantom{\rule{0ex}{0ex}}\text{The specific risk-weighting factor is}\\ \text{equal to:}\\ SRWF=100\phantom{\rule{0ex}{0ex}}·\left[\left(\frac{{K}_{A}-A}{D-A}\right)·1.00\right]+\left[\left(\frac{D-{K}_{A}}{D-A}\right)·{K}_{\mathrm{SSFA}}\right]\\ \phantom{\rule{0ex}{0ex}}\\ \text{(d)}\phantom{\rule{0ex}{0ex}}\text{SSFA equation.}\phantom{\rule{0ex}{0ex}}\text{(1) The [BANK] must define the following parameters:}\\ {K}_{A}=\left(1-W\right)·{K}_{G}+\left(0.5·W\right)\\ a=-\frac{1}{p\phantom{\rule{0ex}{0ex}}·{\phantom{\rule{0ex}{0ex}}K}_{A}}\\ u=D-{K}_{A}\\ \phantom{\rule{0ex}{0ex}}\\ l=max\left(A-{K}_{A},0\right)\\ e=2.71828,\text{the base of the natural logarithms.}\\ \text{(2) Then the [BANK] must calculate}\phantom{\rule{0ex}{0ex}}{K}_{\mathrm{SSFA}}\phantom{\rule{0ex}{0ex}}\text{according to the following formula:}\\ {K}_{\mathrm{SSFA}}=\frac{{e}^{a-u}-{e}^{a-l}}{a\left(u-l\right)}\\ \text{(3) The specific risk-weighting factor for the position (expressed as a percent) is}\\ \text{equal to}\phantom{\rule{0ex}{0ex}}{K}_{\mathrm{SSFA}}×100.\end{array}$