At Easter they were told the free shares would be priced in the £2.40 to £2.90 ( 3.50 to 4.25) range when they start trading in London on 10 July, valuing the average windfall for an Irish policyholder somewhere between 730 and 1,450.

But the stock market turmoil of recent weeks has forced Standard Life to trim its expectations. Assuming the flotation still goes ahead, the shares will now be valued somewhere between £2.10 and £2.70, paring the average windfall to between 660 and 1,320.

The sliding fortunes of Standard Life policyholders will be closely watched by the 120,000 eligible members of Irish Nationwide, who expect to pocket as much as 15,000 each when the building society is sold in the coming months.

Nationwide members do not have to fret about stock market wobbles dashing their dreams because it is likely that their windfalls will be paid in cash rather than shares. But they cannot escape the markets entirely and a prolonged downturn, which many commentators now fear, would inevitably dampen potential buyers' interest in the building society.

Irish Nationwide cleared the last hurdle to a fast-track sale last week when the government pledged to revamp the building society rule book following intense pressure from its managing director, Michael Fingleton.

This speeds up the sale process, although the way the money is carved up between members remains unchanged from previous building society sell-offs, including Irish Permanent and First Active.

These rules stipulate "one member, one windfall" so that everybody gets the same no matter how much money is in their share accounts or owing on their mortgages.

Fingleton believes that Nationwide is too small to follow predecessors such as Irish Permanent and First Active onto the stock market, opting instead for a trade sale to a bigger financial institution.

Many Nationwide customers agree, preferring cash in hand to a white knuckle ride on the stock markets, although building societies that chose that route in the past have eventually rewarded shareholders handsomely for lasting the pace.

Irish Permanent led the way in 1994, giving 300 free shares per member. These were valued at IR£1.80 ( 2.29) on the first day of trading, yielding an immediate windfall of 685. Today this basic holding would be worth 5,800, boosted by loyalty shares and especially by the 1999 merger that created Irish Life & Permanent. The group still has 130,000 shareholders with fewer than 1,000 shares each on the books, suggesting that many people are hanging on to the free shares they got back in 1994.

It has been a rockier ride at First Active. Its shares tanked within months of coming to the market in 1998, and many customers must have regretted the decision not to jettison their 450 free shares at the flotation price of 2.86.

But payday eventually arrived in 2004, when Royal Bank of Scotland paid 6.20 a share to acquire the former building society, boosting the average windfall to more than 3,000.

Insurance companies are far less egalitarian when it comes to ditching their mutual status, dividing the spoils in favour of customers who have been on the books for longest and especially those with the biggest policies.

Norwich Union gave a minimum 150 free shares to all qualifying members when it went to the stock market in 1997, although some people got a lot more. It also whetted the Irish appetite for carpetbagging, with thousands of people signing up for lastminute policies just to get their hands on the free shares.

The result of that was that, while Ireland made up only 5% of Norwich Union's assets, it accounted for 15% of the insurer's shareholders after the flotation.

Canada Life sparked another carpet-bagging frenzy in the run up its stock market debut in Toronto in 1999.

Takeover speculation meant that the shares always performed well and, when the company was eventually bought out in 2003 by another Canadian insurer, GreatWest Life, the 25,000 Irish people who had held on to their free shares pocketed a 170m windfall.

Scottish Provident was another cash cow for 75,000 Irish people who shared a 500m jackpot, with a minimum 800 payout per member, when it was bought by Abbey National in 2001.

The bad news for carpetbaggers is that they are running out of targets. Once Standard Life goes to market, no other insurance company of any size will remain in customers' hands.

Building societies are also an endangered species and the EBS will be the last of its type when Nationwide eventually demutualises. The new legislation unveiled last week will bolster the EBS's defences against carpetbaggers considerably. Once it is enacted, members will be effectively gagged from even discussing demutualisation.

This privilege will be retained for directors only and, as long as the present board is in place, hell will freeze over before demutualisation is put to the vote at the EBS.