I know very little of places where you can download/have access to historical data. Can we post websites or other businesses that have this, what data it is, how you access it, and what the current estimated cost is? All I have is yahoo finance, which is completely free. Click on the ticker you want to get data for. Click on "Historical Data". You will then have access to that ticker's historical data, including the ability to download it into Excel, which I love. That applies to stocks and ETFs, and at least some indexes, but not sure about other things. For example I do not see it for EUR/USD, here: https://finance.yahoo.com/quote/EURUSD=X?p=EURUSD=X What else does everyone have? Post it all! Thanks!
Read the threads in the data section of this forum. It is all there. https://quantpedia.com/links-tools/?category=historical-data
Another free source for US stocks is Nasdaq.com. Instead of Excel, you may consider stock charting software e.g. Metastock, Ninja Trader or Amibroker. It is more efficient and convenient way of analyzing stock. I use Amibroker and it has a plug-in(AmiQuote) that download several free sources.