I'm thinking of a much shorter time horizon. The problem with long-term investing right here and now is that potential possible futures include many where the long-run risk-asset investor ends up with a big fat zero. Someone, somewhere will have to cough up and accept massive losses to rebalance the economy post QE.
I was being cute. Investing is not trading. Another one of my techniques is to never sell, as long as the dividend yield is better than what I can get in bonds.