My book on Warren Buffett, "The Midas Touch", has just been published in Britain. It contains most of his favourite investing principles. Although time has passed since its original appearance, his ideas today are much the same.
Here is a handful of the central ones. They aren't easy: this is a competitive game.
1. The key to investing is found in this rule: buy a share as though you were buying the whole company.
To do that, you have to know what the enterprise is worth. Therefore, the investor should live in the world of companies, never of mathematical formulae.
In the latest annual meeting of Berkshire Hathaway, Buffett's company, his partner Charles Munger put it this way: "The worst decisions are often made with the most formal projections. They look so professional that you begin to believe the numbers are reality.
"You are taken in by the false precision. Business schools teach this stuff because they have to teach something."
2. A recent heresy is that market volatility equals risk. Quite the contrary!
For a serious investor, volatility creates opportunity. To use my own language, investment opportunity consists of the difference between reality and perception. High volatility increases that difference, and thus increases opportunity for the knowledgeable investor.
Mr Buffett says sardonically that he favours the dotty "efficient market theory" because it creates more opportunities for him.
3. As to growth versus value, Mr Buffett observes that "value" should include projected growth, notably "growth at a reasonable price" or Garp.
He looks for companies with a business "moat" around them that should have steady, reasonably predictable growth.
Perhaps a better phraseology for the growth versus value dichotomy might be "high growth" versus "bargain hunting". The analytical techniques, and investor temperaments, in the two approaches are quite different. One calls for a futurologist, the other for an accountant.
That said, for a taxpaying investor long-term growth is more convenient and more tax-efficient than seeking one bargain after another.
4. High technology, most emerging markets, leveraged buyouts, real estate and other hard to appraise exotica might as well not exist for Mr Buffett.
He follows the safest approach: stick to what you know best. However, many approaches are valid. Your advantage will be the extent to which your knowledge of a valid situation exceeds the market's.
It makes little difference how broad your knowledge is. One correct investment decision is as valuable as another. Mr Buffett says that one should only seek a handful of really big ideas in one's investing career. The key is to be right when you do decide, not to flutter about spreading yourself thin.
5. Investing in bad industries, or turnarounds, usually doesn't work.
A skilled surgeon can excise a tumour but to revive a moribund patient requires a magician. The princess hopes that when she kisses the toad a beautiful prince will spring up. In fact, alas, she will probably end up awash in toads.
6. Businesses that generate cash that they can reinvest at high rates of return over long periods are particularly attractive holdings.
Low-margin businesses that periodically call for more cash from their investors, which they can only invest at a modest rate of return, are a dismal affair. Differently put, if all else is the same, feel free to marry an heiress rather than a pauper.
7. Don't sell a great stock just because it has doubled.
It could be better value afterwards than it was before. The greatest stocks may go up 20 or even 100 times in a generation or two.
Peter Lynch, who built up Fidelity's Magellan fund, points out that the deluded policy of "rebalancing" more or less automatically because a stock has risen is a lot like pulling out the flowers in the garden and watering the weeds. Don't do it!
8. A grave corporate folly is offering your own underpriced stock for the fully valued stock of an acquisition candidate.
In that scenario, instead of paying 50p for £1 of value, you are paying £1 for 50p of value. Lunacy! Still, such situations are often generated by the megalomania of chief executives.
9. Avoid long-term bonds.
"We are bound to have inflation, given current policies. There are a lot of incentives for politicians in all countries to inflate their currencies," Mr Buffett says.
10. To do superlatively well, an investor, like a company manager, must be a fanatic.
By relentless concentration, Mr Buffett has moved billions of dollars from other people's pockets into his own. Alas, he doesn't enjoy what money can buy. He's a miser.
Once, offered a glass of good wine at a dinner, he said: "Just hand me the money." So, it may be helpful in business terms to be that focused, but not necessarily in human terms.
Still, to preserve capital, which is difficult, one should understand the principles, and Mr Buffett's are all good ones.
