Editor's Note: In today's Weekend Edition… what we believe is the single most important wealth secret to succeeding as an investor over time… and avoiding what Bill calls a “ruinous loss.”

Contrary to what most stock market gurus would have you believe, investing success is not all about stock picking.

As Bill says, it's about being in the right place at the right time…

What you are about to read flies in the face of everything your stockbroker or Wall Street adviser will tell you.

It's about the closest thing to heresy you can get in the investing world… and the newsletter business. It's also a key insight if you want to stay wealthy over time.

It is simply this: Stock picking alone won't help you hold on to wealth.

Unless you are very lucky… or very, very talented… you will struggle to pick the right stocks at the right time ALL the time. You will make mistakes. You will mess things up. And unless you have the right discipline in place, sooner or later you will lose money.

That discipline is called “asset allocation.” That sounds technical. But it's really just about how you spread your wealth over different types of investments. This is backed by hard data.

For instance, a well-known study in 2000 by Yale professor of finance Roger Ibbotson and Paul Kaplan of Morningstar showed that differences in asset allocation among mutual funds explained virtually all of the variance in their returns.

Differences in stock picks made virtually no difference to the variance in portfolio returns.

Common Sense Decisions

It's common sense, but you don't put 100% of your wealth in stocks in a savage bear market.

And you don't invest 100% of your wealth in bonds in times of runaway inflation.

This seems straightforward. But you'd be surprised how many investors skip over these fundamental decisions in the rush for the latest “hot stock.”