1. From the S&P 500 prices, remove the prices that are simply repeats of the previous day’s price because they indicate a missing observation due to a holiday. Calculate daily log returns as RtC1 D ln.StC1/????ln.St/ where StC1 is the closing price on day tC1; St is the closing price on day t, and ln ./ is the natural logarithm. Plot the closing prices and returns over time.