Question 5 2 pts Elton and Gruber's groundbreaking work is important because it gives investors which of the following key insights? Select ALL answers that apply: there is a limit to the benefits gained from diversification the benefits of diversification continue indefinitely as we add additional positions to our portfolio to achieve full diversification a stock portfolio should have at least 50 different stock positions an optimal portfolio would have between 20-30 stock positions Question 6 2 pts Which of the following relating to Markowitz's Modern Portfolio Theory are accurate: In recent years the basic assumptions of MPT have been widely challenged By combining different assets whose returns are not perfectly positively correlated, MPT seeks to reduce the total variance of the portfolio return. assets in an investment portfolio should be selected individually, each on their own merits MPT is widely used in practice and its basic assumptions are widely assumed to be at the forefront of portfolio management