The S & P 500 fell but rebounded after the U.S. and Israel launched an attack on Iran, but WTI crude prices were off their highs of the day. The CNBC Investing Club with Jim Cramer initiated a position in Cardinal Health from its watchlist, using the cash from exiting Danaher. Meanwhile, CrowdStrike rose more than 2% after Piper Sandler upgraded the cybersecurity name to a buy-equivalent rating from hold. The analysts believe the nearly 19% year-to-date pullback in CrowdStrike is "overdone". Nvidia shares gained more than 3%. The chip maker was named a top pick in semis at Morgan Stanley, replacing Micron. Despite the gains, shares were still lower year to date.