The risk-weight on "Margin lending against listed instruments on recognised exchanges" is 20% according to APRA's interpretation of the Basel 3 Accord in 'Prudential Standard APS 112 Capital Adequacy: Standardised Approach to Credit Risk, Attachment A: Risk-weights for on-balance sheet assets'.
A bank is considering lending a $100,000 margin loan secured by an ASX-listed stock. How much regulatory capital will the bank require to grant this loan under the Basel 3 Accord? Ignore the capital conservation buffer and the off-balance sheet exposure.