The market is deeply underestimating how bad it can get,” Galy told MarketWatch in a phone interview. He sees a “60% chance that things go quite awry on the trade side,” and a 5% to 10% pullback for stocks “quite likely though eventually temporary” as a result of that.He explains how that trade situation could go pear-shaped: “The worst-case scenario is that just ahead of the G-20, we realize that it’s a no-deal situation, and we get the U.S. imposing much wider tariffs on China, which will retaliate and devalue its currency. That will force the Americans to again increase tariffs.”