Would you expect a portfolio that consisted of the S&P 500 stocks to be more or less risky than a portfolio of Nasdaq stocks?

Would you expect a portfolio that consisted of the S&P 500 stocks to be more or less risky than a portfolio of Nasdaq stocks?

If we constructed a chart like Figure 5-3 for an average S&P 500 stock, do you think it would show more or less volatility? Explain.