Quantopian's community platform is shutting down. Please read this post for more information and download your code.
Back to Community
Questions about backtesting short sales

Hello, I have three questions about backtesting short sales:

  1. how is availability modeled since stock is not always available for borrowing

  2. are dividends on borrowed stocks which the borrower must pay accounted for

  3. when borrowing a stock, can a lender demand back the stock if the price falls too much

2 responses

It's not, I think it is, and technically yes at any time, but it's never happened to me.

Hi Simon and thanks for your reply. I put in a feature request:

https://github.com/quantopian/zipline/issues/1468

The reason I bought this up is because a lot of the interviews I listen to with various traders, I notice a majority of them avoid short selling as a strategy, either because it is too costly or because it is hard to backtest.