I know of no one providing a free API specifically to R. There are some other APIs out there, such as the one provided by RapidAPI, but these are non-official and limited in their free accounts. Before going any further, however, it’s worth mentioning that, even though Yahoo Finance actually had, at some point, an API of its own, apparently due to some legal problems they had to discontinue it. Still, what interests us here is the historical price series, which is for free. The platform will then show you some free information, both technical and fundamental, about the desired company and stock (naturally, the best pieces are kept for Yahoo Finance’s premium accounts). This is not necessarily the company’s trading code at the market, but its representation in Yahoo Finance.

To get the numbers for a specific stock, all you have to do is to search for its Yahoo code (ex: VALE – see figure below).

Yahoo Finance (below) is a website that gives us a good deal of information about the financial market, including information about stock trading.

Download yahoo stock