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!"

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.

Investors have to ask themselves two questions. How much can we grow our investments? And, can we afford our mistakes?

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

How long can interest rates stay negative? Think about this. Not only are you lending your money to governments, but you're paying them interest for the privilege of doing so.

[When] the market is trying to get to terms with, first, lower global growth, particularly out of emerging markets and China. And, second, the market is worried the central banks have run out of ammunition. So put these two things together, and then investors are repricing the market lower.

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.