The panic buying by China’s newly-minted, day trader hordes (who, as a reminder, are unwittingly conducting the greatest experiment in greater fool theory investing in history despite the warnings of China’s securities regulator) took a breather on Tuesday which we think presents as good an opportunity as any to assess what factors might intervene to derail the self-feeding margin madness that has Shanghai and Hong Kong partying like it’s 1999 on the Nasdaq.