Margin requirements are designed to control the default risk inherent to commitments undertaken by traders writing options. Much like similar institutions, the Tel Aviv Stock Exchange first adopted a system based on the Standard Portfolio Analysis of Risk (SPAN), which sets required levels of...

This paper introduces the quantile regression- based Distance-to-Default to Probability of Default (DD-PD) mapping, which links individual firms' DD to their real world PD. Since changes in the DD depend on a handful of parameters, the mapping easily accommodates shocks arising from quantitative...