It's not that they don't want to rock the boat; it's just that, when things get choppy, they make sure nobody is watching from the shore.

So it's always worth paying attention when a fund manager chooses to air his concerns publicly, especially when, by breaking his silence, he is also breaking ranks with the rest of the industry.

Paul McCarville, a director of Setanta, the asset management arm of Canada Life, believes the huge exposure of pension funds to Irish stocks and shares could be a disaster in the making.

So far, so predictable. For many years, financial experts have fretted about the lopsided nature of pension investments, with Irish equities accounting for 18%-19% of the average managed fund.

To put this in context, remember that the Irish Stock Exchange accounts for only a fraction of 1% of the global market in stocks and shares.

What is noteworthy about McCarville's comments, aired in a trade publication, is that they marked the first time that such concerns have been raised publicly within the fund management industry.

He believes that only a herd mentality can account for the fact that so much of our financial futures is riding on a handful of homegrown blue-chip companies, led by the banks.

As long as every manager remains stuffed to the gills with Irish equities, they find safety in numbers. What's the harm in taking such a big punt on Ireland when all the other guys are up to the same thing?

Skewed it may be but there's no denying that this strategy has paid off handsomely in recent years as the Iseq raced ahead of other stock markets to deliver record returns. But what happens when the party begins to fade, especially if the killjoy turns out to be a property downturn?

According to McCarville:

"When the property boom currently fuelling the economy slows down, ceases or even goes into reverse, it will be interesting to see how quickly allocations to Irish equities are reversed, and whether Irish or overseas investors are quickest on the trigger."

Defenders of the status quo will have no difficulty picking holes in this argument. They profess full confidence in the Irish stocks in their portfolios as well as the economic factors driving their strong earnings.

So why should they go against their instincts and begin offloading shares just because someone else thinks they may have too much of a good thing?

They must also suspect McCarville's motives, especially as Setanta's recent performance has been hit by its decision to take its own medicine by ditching Irish equities while they are still flying high.

Yet, there is no denying that investors who keep their money close to home face slim pickings. AIB and Bank of Ireland on their own make up one-third of the Iseq. The banks together account for 45% of the index. And the top five stocks . . . the big two banks, CRH, Anglo Irish Bank and Ryanair . . . make up 60% of the Iseq.

To make matters worse, many of these stocks tend to move in the same direction, creating a domino effect when things go wrong.

According to Setanta's analysis, the share prices of the big two banks have shadowed each other almost perfectly over the past decade so that, if AIB takes a wobble, Bank of Ireland gets caught in the tailwind.

It's the type of risk that investment eggheads might refer to as having all your eggs in one basket. Nobody minds too much attention when times are good. But fund managers will have to duck for cover if a localised disaster, such as property crash, causes their Irish stars to lose their lustre.