The initial margin requirements for a portfolio of derivatives are typically calculated using a risk model. Common risk models are procyclical: margin requirements for the same portfolio are higher in times of market stress and lower in calm markets. This procyclicality can cause liquidity...

The requirement to post initial margin on derivatives transactions is a key feature of the post-crisis reforms of the OTC derivatives markets. Initial margin requirements are usually determined by risk-based models. These models typically require increased margin in stressed conditions: they are...

We quantify the size of a fire-sale externality in the derivatives market in the absence of a macroprudential buffer on top of microprudential initial margin requirements. We show how this varies over the financial cycle with market volatility. We then assess the ability of a macroprudential...