It is exceedingly difficult to make predictions, particularly about the future"

That quote, from Danish physicist Niels Bohr (1885-1962), and subsequently attributed to Sam Goldwyn and Yogi Berra in varying forms, is an undeniable truth that anyone who has tried their hand at forecasting the stock market can attest to.

I thought it would be an interesting exercise to demonstrate just how difficult it is, with a few examples of predictions or market calls that have been made in the last five years, plotted on a chart of the S&P 500.

My sincere apologies if your favorite bearish prognosticator isn't on here, there were just too many to choose from, so I tried to get a mix of one-timers and repeat-offenders. I hope they all have a sense of humor, and I imagine that given most are in the public eye they already have a fairly thick skin, as it must be hard to take the heat they do in such an unforgiving arena. And yet many still try their hand, unbowed by the relentless bull market before us.

To be fair, some of these predictions are still current, so you never know, they could still be right!

It's interesting that some repeat-offenders are getting a bit smarter, by being a little open-ended or less specific with their timing, and most recently pushing their forecasts out a full year ahead of when they make them. Should it come to pass before then, they will probably have the gall to say they were early!

The point is, prediction is futile, and besides, it isn't even necessary to make money in the market.

Whatever your methodology - fundamental, technical, value, momentum - if you're in the business of trading for a living or managing other people's money, you know as well as I do, it's about assessing probabilities, risk/reward, position sizing, being disciplined and managing risk, knowing where and when you're wrong.

But there's very little evidence of that on show in these market calls, and why should there be? Most of them aren't money managers, they're economists, newsletter writers, authors, or columnists. Most can predict without consequence because they're not held accountable and they're not regulated. Why you would seek their advice then is beyond me, but many do.

If I need advice on something, I tend to seek the opinion of people who already do it for a living. In my experience, people who have been successful and have something worthwhile to share often got help themselves from others along the way, and are happy to give back.

If you want help managing money, ask a money manager, if you want financial advice, ask a financial advisor, and if you still need a prediction, you need to re-read this post.