The stock market has had a nice run-up of late. So could now be the time to get back in the market? Not so fast. I think you never should have gotten out in the first place. And by getting in right now, you will have already missed the run-up.

If you go back to when things were at their darkest, I was taking panicked call after panicked call from people who wanted to jump ship. Many of them sold all their holdings and stopped investing. But by going to the sidelines, they only locked in their losses and missed the big upswing.

We as humans react so emotionally to the ups and downs of the stock market that we conspire against ourselves. In reality, the time to be excited is when things are at their bleakest and the time to tread lightly is when things are going great in the market.

If you think back over the years, I've always said that I'm the turtle. I plod along with my investments, practicing "steady as you go" and diversifying my money while dollar cost averaging. I always tell people to keep their eye on the horizon. The younger you are, the more stocks you need. The older you are, the less so. In simple terms, my strategy is boring.

But the opposite approach -- hopping in and hopping out of the market willy-nilly -- has danger at all turns. Even the greatest professionals mess up when they try to time the market. It is my belief that plain vanilla index funds or exchange traded funds will, over time, outperform the portfolios of the geniuses who pop in and out.

Being reactive is not my game. If you like sport, fine, then feel free to jump in and out as you see fit. A lot of people have been asking me about Apple stock, now that the company's value is down by about 35%. To buy their stock with a small part of your money -- your "play money" -- is fine. But sinking everything you've got into Apple? That's not my game.