Input ^NDX and ^GSPC (Nasdaq-100 and S&P500 respectively) as the input tickers. These are Yahoo Finance’s codes for those respective indices. Alternatively, you can input QQQ and SPY, which are ETFs that track those indices but there will be less historical data since ETFs come after indices.
Coincidentally, I made an app to do exactly these types of historical comparisons of returns, with much greater fidelity.
Input ^NDX and ^GSPC (Nasdaq-100 and S&P500 respectively) as the input tickers. These are Yahoo Finance’s codes for those respective indices. Alternatively, you can input QQQ and SPY, which are ETFs that track those indices but there will be less historical data since ETFs come after indices.