Negative interest rates and company stock buy backs might be able to allow markets to keep going for a while. Negative rates cause investors and sovereign wealth funds to pour money into equities. The Bank of Japan owns 50% of the ETFs in Japan. That should scare people.

Stock buy backs artificially inflate reported company earnings. Companies take on cheap debt to buy back shares of their own company (at historically high valuations) to keep investors happy and beat earnings estimates.

This game of musical chairs can run for a while.