Does Diversification and Market-Timing Make Sense?

It has been a busy week, Singapore is having its General Elections, and given my stake and ownership in this country, I have been focusing on that. 

Nonetheless, here's an interesting video from Forbes on a fund manager who talks about diversification and market timing. None of it is original wisdom, but investors might want to take heed on the wisdom of diversification and the folly of timing. 

Or not? It's a tough question, almost 2 camps of people with opposing views. My take is, non-professionals should diversify, in fact just use an index fund, and forget about timing, if they have a long horizon (those who don't are best served through just remaining in money market assets). But well, many others would suggest otherwise.  

Watch this, for another viewpoint.