Investors are showing a growing willingness to take on risk, but many are questioning the sustainability of the US bull market.
Chris Watling, global economist and chief market strategist at Longview Economics, warns that the market is due for a pause.
"The bull market in the States [US] rarely goes more than two, two and a quarter years without a big break. It doesn't have to be a bear market, but certainly a big break, a multi-month pullback. Maybe it's 10%, maybe it's a little bit more than that," Watling says, citing the S&P 500 (^GSPC) trends going back to the 1970s.