Section 1000.315 - Is a recipient required to report changes to the Formula Current Assisted Stock (FCAS) on the Formula Response Form?(a) A recipient shall report changes to information related to the IHBG formula on the Formula Response Form, including corrections to the number of Formula Current Assisted Stock (FCAS), during the time period required by HUD. This time period shall be not less than 60 days from the date of the HUD letter transmitting the form to the recipient.(b) The Formula Response Form is the only mechanism that a recipient shall use to report changes to the number of FCAS. 72 FR 20025 , Apr. 20, 2007