You manage a portfolio of stocks valued at $10 million. The beta of your portfolio relative to the S&P 500 index is 1.5. You want to hedge your portfolio using S&P 500 futures contracts. Each S&P 500 futures contract is based on an index level of $250 times the S&P 500. Assume the current level of the S&P 500 index is 4,000. How many futures contracts would you need to sell to hedge your portfolio?