$1.$ Calculate daily S&P$500$ index returns and daily cumulative returns over the sample period $($Jan$.2,2019,$ to Dec $28,2023)$:

$2.$ Compute daily cumulative returns:

$3)$ Calculate the mean and standard deviation of daily returns.

$4)$ Plot the cumulative returns over the sample period $($X$-$axis: Date, Y$-$axis: Cumulative Return$).$

$5)$ Explain the plot by identifying trends, significant events, or periods of high volatility.