Every weekday, the CNBC Investing Club with Jim Cramer releases the Homestretch — an actionable afternoon update, just in time for the last hour of trading on Wall Street. Markets are off to a mixed start to the week. The S & P 500 traded higher for most of the early afternoon, but the bulls struggled to keep the ball in the air. What held back the broader market's attempted rally was oil. WTI crude climbed 4% as markets awaited more clarity on a potential deal with Iran to open the Strait of Hormuz. Also not helping the bull's cause…