The positive vaccine-news rally has run its course, says Hercules Investments' James McDonald
"There are expected vaccine setbacks: there are supply chain slowdowns and yesterday's allergy warning is something we need to pay close attention to. The stimulus hopes are fading and we have never had a market run up this high for this long in history." James McDonald, founder and CEO of Hercules Investments, told CNBC's "Squawk Box" Thursday. "There are just too many risks in the market relative to the run up that we've had."