Personal Finance: `It's all part of the sea change in British attitudes to investing in shares'

THE PRIVATE investor share-buying frenzy was further fuelled this week with the launch of services that allow investors to borrow money to buy shares and deal in options contracts online.

Leaving aside the fact that options are over-complicated things best left to big City institutions, it is the introduction of lending money for share purchases - or "margin trading" - that rings alarm bells. After all, margin trading is commonly held responsible for the 1929 Wall Street Crash.

Margin trading has been around a long time in the US but has never been available to the general public over here. The idea is that an investor who wants to buy some shares and who lacks the cash, or who wants to "gear up", borrows the money from his broker. The shares act as security to the loan. If the shares drop in value, the broker can demand more cash to make up the difference - in other words, make a "margin call".

If share prices go up, you can make a lot of money more quickly by using margin trading. But if the shares drop, your portfolio is devalued, and the broker wants extra lolly.

In the 1920s, Wall Street experienced one of the great stock market booms of history. As investors became more and more convinced that prices could only go up, so they borrowed more on margin. When the fall came, all the margin investors wanted to get out at once.

So the introduction of margin trading to a mass market by US-owned online brokers TD Waterhouse, E*Trade and DLJ Direct next year will be of more than academic interest.

But many market watchers think margin trading will be good for the UK. In the hands of experienced investors who know what they are doing, it should allow more investing to be done and boost the liquidity of the market into the bargain.

There's the rub, though. I worry that too many inexperienced investors, who don't realise the negative as well as the positive power of margin trading, will pick it up as "the next big thing".

It's all part and parcel of the sea change in British attitudes to investing in shares. Dealing volumes have doubled in the last couple of months. This also seems to be one of the first times when you, the private investor, have powered the stock market forward, while the City institutions have sat back, worrying about the Millennium Bug.

It will be interesting to see how far this new mania for shares takes away from the lure of Individual Savings Accounts (ISAs). The savings industry is preparing for a big sales drive for ISAs in the spring, as the memory of their more popular predecessors, PEPs, finally fades. I wonder whether people who would normally buy ISAs may now prefer a punt on an Internet stock instead.

As long as you know what you are doing, and never invest money you can't afford to lose, margin and options trading and net stocks are all reasonable ways of investing your money. Just do your homework first.

Have a very Happy Christmas and a careful New Year.

John Willcock is the Personal Finance Editor of The Independent