I'll defend Larry on this one, he isn't talking about market timing, he's talking about risk management. The S&P500 is twice as risky at 20x earnings than at 10x earnings, so if your risk profile hasn't changed, you should be adjusting your portfolio to compensate. You can do this in a number of ways, by scaling back the equity weighting in your portfolio, by rotating into defensive / value stocks, by increasing investment in low to negatively correlated assets / currencies, or by using a variety of options strategies like protective puts or covered calls (Larry's use of ZWH / ZPW ETFs are a bit more advanced, but yes, they can be used to reduce portfolio risk when intelligently combined, although I would not recommend these to non-pro investors). 

These are textbook portfolio management techniques that have nothing to do with market timing, which is about speculating about the direction of the market. 

https://ca.linkedin.com/in/peterfilippakis