Shares of Apple Inc AAPL.O, Amazon.com Inc AMZN.O and Alphabet Inc GOOGL.O also gained between 0.6% and 0.7%. By Shreyashi Sanyal July 21 (Reuters) - The S&P 500 and the Nasdaq were set to open higher on Thursday as electric automaker Tesla topped Wall Street's profit target, while futures tracking the Dow struggled for direction. While market participants took comfort in the positive results, they continue to await anxiously a Federal Reserve meeting next week where policymakers are expected to raise interest rates by 75 basis points to curb runaway inflation.