Take the lucky members of a syndicate put together by Liberty Asset Management, an investment adviser that shares a parent with insurance company Friends First. They ponied up an average of £350,000 each ( 500,000) to buy a London property for £13.7m. Three years and nine months later, they flipped the building for a cool £20.2m, netting returns of more than 100%.

The investors had two things in their favour: a strong property market and the magic of gearing, which magnifies your returns in a rising market.

Here's how it works.

Syndicate members put up 10m to buy a 100m property, borrowing the rest from the bank. The value of the building rises to 110m, with all of the gain going to the investors.

So even though property prices have gone up a modest 10%, the investors have doubled their money.

An interesting footnote is that the building bought by the Liberty syndicate was leased to the Really Useful Group, owned by Andrew Lloyd Webber. He became known as the man with the biggest mortgage in Britain when he borrowed £35m ( 50m) against his personal property to speed up the purchase of the musical theatre company.

After clearing the mortgage by refinancing the company's debts last week, the theatre mogul was quoted as saying: "It's a marvellous feeling no longer to be known as the man with the biggest mortgage in Britain."

But debt holds no fears for gung-ho Irish investors.

Gearing has transformed them into paper millionaires and, having profited from property, many are now ready to test the waters in other asset classes.

Like property, the stock market has been on a roll for some time and last week the Dow Jones industrial average finally recovered the ground lost since the dotcom bubble burst six years ago. Banks are generally wary of lending to invest in equities because the stock market is such a topsy-turvy place.

But they will quickly change their tune if there is some sort of guarantee of getting their money back should things go wrong.

This explains the attractions of guaranteed bonds, which promise stock market-style returns with your money back at maturity. On the surface they sound like a more suitable bet for widows and orphans than high rollers.

But the big boys aren't investing their own cash;

they're using the bank's money, knowing that the guarantees mean they can be sure of having enough to repay the borrowings at maturity. So it's a free ride on the stock market, where the only risk is that the bond won't make enough to cover the interest on the loan.

The trouble with this fast-track route to riches is that, at a time when asset values are powering ahead across the board, we easily forget that gearing cuts both ways. If you borrow for an investment that goes wrong, you lose your shirt.

If the property market had dropped 10%, the investors in the example above would have been completely wiped out.

A few forlorn voices have cautioned about the risks of borrowing to invest. The Financial Regulator has urged investors to think twice before signing up for geared tracker and investment bonds but, judging from the continuing demand, few are paying attention.

The Pensions Board has had even less success. The government ignored its warning that it would be dangerous to allow pension funds to borrow. By relaxing the rules, it has opened up a new front in the battle for property, with investors adding debt to their tax-free pension savings to buy even more bricks and mortar.

The industry watchdog believes debt adds an unacceptable layer of risk to pension investing, exposing investors to dangerous over-reliance on a single asset class.

But for as long as you can double your money in four years, who's going to listen?