# Stock borrow cost timeseries

I am looking to increase the robustness of some equity strategies that I am working on. Apart (maybe) from brokers is there anywhere online (and preferably for free) that has historic stock borrow percentages or abosulte borrow costs available for borrowing stocks? I want to factor the cost of borrowing a stock into whether I want to take a position (if the cost is high then there maybe not enough alpha to justify the position to be taken etc).

Thanks

• The rates vary by broker, by client tier, by ticker, and by time of the day really (first come first serve). ADRs may be subject to additional fees when shorting, but those fees tend to be per transaction. Mar 24, 2021 at 11:37

This website has detailed time series data for borrowing cost and shares available, sourced from IB. You can also retrieve the data using the following API endpoint: https://iborrowdesk.com/api/ticker/{symbol} (replacing {symbol} with the proper symbol ticker).