Investors should keep a close eye on these five key developments as they kickstart their trading day: 1. Market optimism prevails as major averages see gains, with Dow Jones hitting a record close. 2. Federal Reserve Chair Jerome Powell signals readiness to cut interest rates before hitting 2% inflation target. 3. Former President Trump makes his first appearance since the assassination attempt at the Republican National Convention. 4. General Motors CEO Mary Barra casts doubt on meeting EV capacity target of 1 million vehicles in North America by next year. 5. Apple CEO Tim Cook hints at upcoming developments at the company's annual developer conference.