I am currently building a stock trader and am making the part where you have to enter a ticker to trade. The Database that I am using is from Yahoo Finance but I need to see if the users input is valid. I tried putting NYSE, NASDAQ and S&P500 all in one list but there was some the weren’t there and some that wasn’t supported. I saw a similar post to this, but it was pretty outdated and none of the answers were helping me. I want to make a list that has all of the Yahoo Finance Tickers.