As of August, retrieving quotes from Yahoo has not worked for me. Alphavantage still seems to work as long as I get my quotes prior to 0400 GMT. The working solution suggesting v8 URL returns a message of unauthorized and no date or price for the selected stock. I am suspecting that Yahoo is trying to make it difficult to download prices into accounting and other financial analysis software.
Has anyone found a solution that works with either Yahoo or a different US-based API? I am looking for US-based stock data.