Basically, the Fed has done everything that can with near-zero interest rates and QE to stimulate economic activity, but their monetary policy efforts have created incentives (like companies issuing bonds and using the money to buy back stock and issue dividends) which artificially have inflated the market, and the Feds efforts have diminishing returns over time. Unless the government steps in with fiscal stimulus (like tax breaks or spending on infrastructure, etc.) then the market is out of fuel. Kass sees this unlikely in an election year. Monetary policy can only do so much, and it makes for asset bubbles, like the one Kass sees in the stock market. So Kass is shorting the market. He says that if that is too aggressive for you, then consider putting your money in cash, and waiting for this reckoning to play out.