Australian dollar and Brazil real bulls, time to take notes on a warning from Stephen Jen, founder of hedge fund SLJ Macro Partners and a widely followed currency strategist: Jen doesn't subscribe into the hard landing story, but he argues that even a soft landing could be "quite negative" for Australia and Brazil.

"If manufacturing and housing construction investment does falter in China, demand for industrial metals will weaken, which should in turn undermine the Australian dollar and the real, he says.

Jen also argues that the PBOC's monetary easing is reactive in nature and not proactive, thus the chances of the PBOC helping to reflate global asset prices are slim. If the PBOC merely constrains the size of the growth deceleration, "it is not clear why US equities should go higher," he says.