David Prosser: Stay calm, like Buffett the long-termer

Should you pull your money out of the stock market, now that shares have given up pretty much all of the gains they've made since the start of the year? Well, while I'm finding it difficult to get a clear picture from the investment crystal ball, the answer is almost certainly no - unless you shouldn't have bought into shares in the first place.

As my colleague Jonathan Davis explains much more eloquently on page 15, the key to successful stock market investment is to set out a clear strategy and to allocate your assets accordingly. If you've done that, short-term volatility - sharp price rises or falls - should not be allowed to blow you off course. Let's put it another way. Investing in the stock market is a means to an end, rather than an end in itself. The only reason to hold money in shares is that you have decided this is a sensible way to achieve a future financial objective - either a specific need or for a general rainy-day fund.

If that objective is less than five years' hence, the stock market is the wrong way to go about achieving it. There's just too much risk of short-term fluctuations in share prices jeopardising your plans. If, on the other hand, your goals remain some way off, this week's disappointments - or, for that matter, the highs we hit in March and April - are pretty irrelevant.

Market timing is a mug's game. Warren Buffett, the world's best-known - and richest - investor, last week reported another golden year for his clients. He has made his money by choosing shares carefully and then holding them for the super long-term. By all means review the investments you have chosen regularly, but don't be fooled into thinking you can trade your way out of trouble.

One final thought. If you invest in the stock market through the regular savings plans on offer from many fund management companies - an approach often championed by Save & Spend - you have even more reason not to be unnerved by the events of this week. Thanks to a statistical quirk known as pound-cost averaging, your monthly investments are buying more stock market exposure for your money, boosting future potential returns.

* One reason why stock markets have been falling is that investors expect interest rates to rise, both here and in the US. That is good news for bank and building society savers. In a rising interest-rate environment, the first accounts to start paying more are fixed-rate products, which are priced in line with expectations about what will happen in the future.

So it is that the best deals available to savers right now are in the fixed-rate market. Top of the tree is Dunfermline Building Society's offer of 5.55 per cent interest, a rate that is fixed until the end of July 2009.

If you can afford to tie up your cash, such products are worth considering. But don't assume that all savings accounts will rise with the tide - and missing out could be painful.

Inflation has increased from 2.4 to 2.6 per cent over the past month. That means a basic-rate taxpayer now needs to earn at least 3.25 per cent before tax in order to earn a positive real rate of return on their cash.

* Savers' gains, of course, are borrowers' losses. Back in January, the cheapest two-year fixed-rate mortgage was priced at around 4.2 per cent. Today, the best deal costs 4.5 per cent.

However, while some analysts have now begun recommending tracker mortgages as better value than fixes, I think that misses the point. A tracker deal, where what you pay moves up and down in line with the Bank of England base rate, may well be cheaper today. But the appeal of a fixed rate is not its cost - it's the certainty it provides about the cost of future repayments.

In a world where interest rates are expected to rise, fixed-rate deals are more valuable, even at a higher price than four months ago. If you're at all worried about coping with rising interest rates, a fix remains the right deal for you.