I think there are two paths.

Fundamentals, in the longer term fundamentals will dominates and yield concrete returns.

Psychology, in the shorter term playing in momentum, large gains can be returned by trading on emotions.

Fundamentally the markets are over bought but the correction might be years off.

Psychology the markets may move a lot higher before any correction and a ton of money can be made by sticking around for a bit longer.

History indicates that the markets will correct but it can't say when.

If I had stayed in the market my current net would would be much greater today but since I am out of the market my net worth is only decreasing a tiny amount annually.

How much can you stand to lose and how likely are you to catch the falling knife.

TEK