We propose a model to describe stock pinning on option expiration dates. We argue that if the open interest in a particular contract is unusually large, Delta-hedging in aggregate by floor market-makers can impact the stock price and drive it to the strike price of the option. We derive a...

We propose a model to describe stock pinning on option expiration dates. We argue that if the open interest in a particular contract is unusually large, Delta-hedging in aggregate by floor market-makers can impact the stock price and drive it to the strike price of the option. We derive a...

We model and study the behavior of bankrupt stocks. We are interested in the dynamics of stocks and options, and in particular the cost of establishing positions with negative delta.This extends a model of Avellaneda and Lipkin which was used to model hard-to-borrow stocks. This model is a...