jGnash currently uses Yahoo as the source for securities information such as price, dividends, splits, etc.
The Yahoo API has fluxed over the past couple of years after Verizon purchased them. The API's seem to have settled, and additional change is possible.
I'm considering adding support for IEX Cloud as backup/alternative to Yahoo. IEX can also provide information on Crypto currencies and exchange rates
Use of IEX would require opening on an IEX Cloud account. They do offer a "free" Starter account which would be sufficient for most users, but a basic paid account starts at $9/month.
Other suggestions are welcome.
Thanks,
Craig