The volatility of equity markets has increased dramatically after the outbreak of COVID 19. The VIX index increased from 22.92 in February 1, 2020 to 335.7 in May 1, 2020. The Vix index measures 30-day expected volatility of the S&P 500 Index, which tracks the stock performance of the 500 largest US public companies. On the other hand, the S&P 500 Index has risen from the low level of around 2600 in March 2020 to over 4700 recently. a) Does the rise in Vix represent an increase in systematic or unsystematic risk? Explain. b) Under a mean-standard deviation portfolio choice framework, explain the movements of Vix and the S&P 500 Index. You may want to use diagrams.