The U.S. stock markets, notably the Nasdaq and S&P 500 indices, have been hitting new highs almost every day in July, and have shown a near-uninterupted climb since March 2009. “Investors see a great economy,” said Mark Zandi, chief economist at Moody’s Analytics, noting that corporate earnings have picked up after a sluggish two years, and the prevailing low interest rates imply potentially the best returns on stock markets across asset classes. However, “the markets are pretty highly overvalued, so I would be cautious,” and a correction is likely, said Zandi during a recent appearance on  Knowledge at Wharton’s SiriusXM show . Risks of a “cataclysmic event” in Europe over Brexit have receded and the markets seem to shrug off tensions around North Korea, he added. But a correction could be triggered by unmet expectations from the Federal Reserve or from promised tax cuts, he warned.…