There are a few simple rules that will stand you in good stead in the markets: Buy on the dips. Don't trade too often. And never bet against Rupert Murdoch.
The Australian-born media tycoon, 79, has railed against conventional wisdom in a career that has lasted many decades.
Over that time he has taken plenty of rulebooks, ripped them up and come out a winner.
This month, Murdoch will make his most ambitious gamble yet: He will try to redesign the way the internet and the media work by putting up a "paywall" around the Times of London and the Sunday Times, two of his British newspapers.
And this time he is doomed to fail.
It's too late to start charging for newspapers online now. The content isn't good enough, and newspapers themselves are a product of technologies that simply don't work in a digital economy.
All Murdoch is going to achieve with this move is to kill off one of the most famous media brands in the world.
It isn't hard to see Murdoch's motives. The economics of the newspaper business are in a terrible state. Circulations are in steady decline. Their websites don't draw enough advertising to compensate for what they are losing from their print revenue.
Many papers are now losing money. And businesses that don't make money don't survive over time. No matter what they try, most newspapers we are familiar with won't exist in a decade.
Bold move
Murdoch has decided not to simply stand by and watch the titles die slowly. Starting this month, News Corporation, the owner of both the Times and the Sunday Times, will start charging for access to papers over the web.
It will cost £1 (Dh5.30) for a day, or £2 for the week.
It is a bold move. Certainly, anyone who cares about journalism should hope it succeeds. There is little sign that internet advertising will ever be strong enough to replace the revenue that used to come from selling printed newspapers.
One of Murdoch's newspapers, the Wall Street Journal, already charges for access to parts of its online edition. But this is the first attempt by one of the big, international, general newspapers to put up a paywall around its whole website.
Somebody has to try it, and if anyone could make it succeed, it would surely be Murdoch.
The New York Times, one of Murdoch's competitors, is planning to charge readers next year.
There are several reasons why it won't work.
Price is zero
First, if newspapers wanted to start charging for their websites, they should have started more than a decade ago.
Once you set a price for any consumer product, it determines what people expect to pay for it. In this case, the price is zero.
Second, the product isn't worth the price. That isn't a criticism of the Times in particular.
Even British highbrow newspapers have placed too little emphasis on substance, and too much on entertaining and exciting their readers.
Sensationalism worked as a strategy in the print world, when you were trying to get people to buy copies in a shop, usually with eye-catching headlines. Online, newspapers aim to build relationships with their readership through subscriptions.
That involves creating a higher degree of trust and credibility.
Old technologies
Third, it is hard to see a future for traditional papers on the web. The newspaper provided a bundle of news, sport, business, crosswords, television guides and gardening tips, all organised by a single editor.
That worked fine when our access to news was very limited, but is irrelevant now that we can get all kinds of stuff from around the world with just a few mouse clicks.
Imagine if EMI Group tried to sell us CDs with a selection of some classical, some jazz, some pop.
The customers would be baffled. Likewise, the package that newspaper editors put together doesn't make sense anymore.
Why not get soccer news from one source, television reviews from another, and political commentary from a third?
People will pay for news and entertainment. But readers no longer rely on the one-stop shops that newspapers have always been.
Charging for the Times won't change that. All it will do is push the newspaper into a fast decline rather than a slow one. This is the one time to bet against Murdoch.
