Spreading concerns about the health of the global economy;
Mounting credit stress, expressed for example by a widening in US dollar high yield spreads, from 750 basis points to 900 basis points;
A weakening of the US dollar because, on the one hand, the Federal Reserve postponed its rate hike decision due to disturbing developments outside of the US; most notably in China, where authorities had to intervene to defend the currency;
On the other hand, other major central banks felt compelled to loosen further their already very accommodative monetary policies. Among others, the Bank of Japan surprised investors by adopting negative rates on certain excess cash holdings held by commercial banks;