Probably because Australian investors are proportionally smarter...

Probably because Australian investors are proportionally smarter than our friends across the Pacific. No amount of quantitative easing, stimulus packages or social welfare spend is going to match the wave that is coming. There are no economic levers that can wage a war against an enemy that can't be seen with the naked eye. It can never be wiped out yet there are many people who have this problem / solution belief about the situation. It's not like that. It can never be stopped. In case it wasn't clear to many, the plan is to infect around 60% of the population in an ordered and methodical manner such that our ICUs are not overwhelmed. This is not a fast process and the major parts of the economy are closing down for the foreseeable future. Probably at least a year, maybe longer. That's why these stimulus packages etc are pissing into the wind. Sure they'll help alleviate the downturn for some but it won't do anything in the path of the economic avalanche. Secondly, not including the disaster that is unfolding in developing nations, the USA itself is heading towards a huge crisis in their ICUs. Alas, too little, too late.