Quandl is a data provider that brings together over 20 million financial and economic datasets from over 500 sources. Many of these datasets are free and can be easily accessed via the Excel Price Feed Add-in.
For example, here is an extract from one of the weekly Commitment of Traders reports issued by the US Commodity Futures Trading Commission (CFTC). This data can be made available in your Excel spreadsheet using an Excel Price Feed formula:
In order to access Quandl data via Excel Price Feed you need to set up your Quandl API Key. If you don't yet have a Quandl API key or account then you can sign up for a free account here , it only takes a few minutes.
1. Go to your Account Profile page and copy your API key to the clipboard (select it and use CTRL-C or right-click and select "Copy").
2. In Excel select the "Configuration Pane" from the Add-in toolbar:
3. Select the "Quandl" tab and paste your Quandl API Key into the "API Key" box:
4. You can now use the Excel Price Feed Quandl formulas in your spreadsheets.
Quandl imposes rate limits on data access. There is a limit of 300 calls per 10 seconds, 2,000 calls per 10 minutes and a limit of 50,000 calls per day.
Users of free datasets have a concurrency limit of one; that is, you can make only one call at a time and have an additional call in the queue.
There is more information around rate limits on the Quandl website.