Investors might consider a portfolio tweak.

Mum and dad investors who bought shares in the big stock market floats and privatisations of the 1990s might be sitting pretty. Experts say it's exactly these type of shares - large, defensive blue chips paying good dividends - that could shine if the market becomes more volatile.

CommSec's Mums and Dads Index was created to reflect a series of major stock market floats, privatisations and demutualisations of the 1990s.

The composition of the index has changed over the years due to merger activity - Colonial acquired by CBA, TAB by Tabcorp Holdings and Coles Myer by Wesfarmers.

Today it comprises nine stocks: AMP, CBA, Insurance Australia Group (IAG), Qantas, Suncorp-Metway, Tabcorp Holdings, Telstra, Wesfarmers and Woolworths. Several of these companies have recently been stellar performers, out-gunning even a surging market.

Early this month, Wesfarmers and CBA were both up by more than 80 per cent from a year earlier and Qantas was up 50 per cent. However, others have been less than impressive.

Tabcorp rose just 8 per cent and IAG was up 5 per cent. Telstra and Woolworths both fell.

The result was that, overall, the Mums and Dads Index in early February was up just 10 per cent from a year earlier, compared with a 34 per cent gain for the All Ordinaries Index.

Yet during 2008, when the market was crashing, it was the Mums and Dads Index that outperformed, down 26 per cent for the calendar year, while the All Ords plunged 43 per cent.

"Investors who are perhaps more focused on dividends than on capital appreciation might be able to live with this sort of performance," says Craig James, chief economist at CommSec. "Certainly you will be supported in the bad times. But investors would probably be better served by having more of a diversified mix.

"The Mums and Dads Index is a defensive-type portfolio. It does not have BHP Billiton or Rio Tinto or any other mining or energy stocks. Nor does it have any of the specialty retailers, which did very well last year, or any media companies."

For investors looking to future long-term performance, it is the lack of resource stocks in particular that is now seen as a drawback.

James recommends adding companies such as BHP and Rio Tinto to the portfolio. He says developments in Asia are likely to continue as a significant long-term driver of the Australian economy and notes that, despite the recognised quality of most of the companies in the Mums and Dads Index, few have much exposure to Asia.

Ivor Ries, head of research at E.L. & C. Baillieu, agrees: "BHP and Rio Tinto together make up 11 per cent of the All Ords. If you do not own them you are basically betting that China is going to fall in a hole and never recover."

So as the market possibly enters stormy waters, by tweaking their portfolios the mums and dads could yet come out ahead.

Calling Telstra

It's hard to believe that little more than a decade ago investors were buying Telstra shares for more than $9 thanks to the company's stability, high dividend and central position in the booming telco industry. Yet early this month it was languishing at about $3.40. In the 10 months to January when the benchmark S&P/ASX 200 Index rocketed ahead 57 per cent, Telstra shares fell 4 per cent.

"Telstra has been going nowhere. It has a high dividend but with so much uncertainty related to the government's broadband network, the prospects ... are bleak," says Michael Heffernan from Austock.

CommSec's James points to increasing competition in many of its businesses and growing saturation of the mobile market as further negatives.

E.L. & C. Baillieu's Ries says: "If the government achieves its plans to separate Telstra, then confidence in the stock is probably going to go down even further."