A big comeback for stocks, as US futures surge after Wall Street swings back from a negative session and the Nikkei gains more than 4 percent. The Fed says it will begin buying individual corporate bonds on top of ETF purchases, in what is seen as another shift to more active market intervention. Meanwhile the WHO calls for an investigation into new coronavirus clusters, as the outbreak in Beijing grows and hospitalizations in Texas hit an all-time high. In the UK, Prime Minister Boris Johnson says a Brexit deal by the end of July is possible, after talks with EU leaders end with a positive tone despite key sticking points.