Markets going up is not always a bullish signal

Well we are very overbought, but I'd like to put things into perspective. Whereas Trump has said he will make America great again. So far this year numerous markets have done very well, Mexico, Brazil. In Asia we have many markets up 10 percent and more. So I think the question of Asset Allocators ... the big question for 2017 is what will perform relatively well - Emerging Markets, Europe or US. I think if you look at the valuations of the US and all the super bulls, they may be right and the market continues to go up. The market also continued to go up between December 1999 and March 2000 and gave back five years of advance. 

So when the market goes up doesn't make me particularly bullish when the valuations are out of sync.

Sell off will be like an Avalanche

As the market goes down it will trigger selling and then it will be an avalanche. 
You don't know what the catalyst will be. But nobody knows the reason why the market peaked out in March 2000, nobody knows why the Japanese market peaked out in December 1989 and so forth. We just don't know but something usually pushes markets down when they are very overbought and when sentiment is very bullish.