Investors should invest on what they know. The biggest mistake is to invest on what they don't know.

I remember when I was growing up, you would go to a bank to open a deposit, and they'd give you a toaster. A free toaster. These days, if you're a company, and you go to a bank, they could easily turn you away! They don't want your deposits anymore.

Most people are under exposed to global assets, including foreign stocks, bonds and currencies.

Investors should be cautiously positioned as the global economy and markets face major uncertainties. The downgrade will be a further headwind to growth and job creation in the U.S.

We normally think if you're going to lend someone money, you should get some reward for doing this. In Europe, it's a tax!

The theory is that if you take interest rates negative, people are going to say, "That's a silly game! I'm not going to lend my money to governments who want me to pay them. I am going to go into the stock market where I can get positive returns!"

Once you start moving [market] lower, then you trigger of all sorts of things. You trigger people who have to sell because they're over-levered. So they sell their winners and their losers. They're just trying to raise cash. So, what you then get is spreading malaise throughout the global markets.