Could baby boomers, whose pervasive influence radically changed politics, culture and other aspects of American life, inflict the same kind of havoc on Wall Street?

For years, some market pundits have worried about what would happen if aging baby boomers, one-time advocates of making love not war and impeaching Tricky Dickie, decided that owning stock is riskier than dropping a tab of LSD copped from an OD'd Grateful Dead groupie. What if retirement to boomers means turning on, tuning in and dropping out of the stock market?

One of those to raise the specter most recently is Hong Liu, who teaches finance at Washington University in St. Louis.

"When millions of baby boomers follow that pattern in a concentrated period of time, the impact on the stock market could be formidable," Mr. Liu warns.

Boomers have a well-deserved reputation for rattling the Establishment. But many market mavens aren't fazed by prospects of a mass boomer exodus from the market. They say demographics and time should blunt the impact of asset allocation decisions made by aging boomers.

"The shift will likely occur much more gradually than traditionally thought," says Stuart Ritter, a certified financial planner with T. Rowe Price in Baltimore.

Baby boomers, born between 1946 and 1964, won't all retire at once, but over a period of 20 years or more, he says. Moreover, most of them can expect to live 20 or more years after they retire. Discounting the notion that they don't want to die before they get old, their retirement savings will have to keep growing for them to afford an extended retirement. That means relying to some extent on stocks.

"You need to be in assets that give you higher, long-term rates of return, which means equities," says Malcolm Polley, chief investment officer for S&T Wealth Management Group in Indiana, Pa.

The notion that retirees should load up on bonds is "the goofiest thing I've heard," Mr. Polley adds.

Managers of target retirement mutual funds, who design their portfolios around an investor's anticipated retirement date, are holding significant amounts of stock even for investors who expect to retire in a few years.

Mr. Ritter says stocks currently account for 67 percent of T. Rowe Price's Retirement 2010 Fund. Vanguard's fund pegged to the same year holds about 57 percent of its assets in stock. Target funds just introduced by Ameriprise Financial's RiverSource Investments subsidiary expect to hold about half of their assets in stocks at the target retirement date and reduce equity exposure to approximately 25 percent 25 years after an investor retires.

The target retirement funds are designed for investors who don't have the time or don't believe they are capable of deciding what proportion of stocks, bonds and other investments to hold.

Their increasing popularity -- assets in the funds have grown from $1 billion in 1996, to $12 billion in 2001 to $70 billion last year, according to the trade group Investment Company Institute (ICI) -- could blunt any boomer backlash.

The industry group's research indicates that although investors tend to lighten up on equities as they grow older, it's more of a tweaking than a wholesale sell-off. A survey of investors ICI conducted last year showed boomers held 59 percent of their assets in stocks, vs. 62 percent for younger generations and 57 percent for older generations.

While their equity holdings are smaller on a percentage basis, they are larger in dollar terms, as are the stock holdings of investors born before the baby boom. According to ICI's survey, the median value of a portfolio of someone born after the boom was $40,000 vs. $74,800 for boomers and $105,000 for pre-boomers.

Sandy West, ICI's director of investor research, says there are plenty of investors coming along to mitigate any stock selling by boomers. Because of 401(k)s and other retirement savings plans, people are investing in stocks at a younger age, according to Ms. West. The median age at which post-boomers purchase their first stock is 25 vs. 33 for boomers and 43 for those born before the baby boom.

Liz Ann Sonders, chief investment strategist for Charles Schwab & Co., says there's an even more influential group of stock buyers than boomers: hedge funds. Their appetite for stocks, as well as the fact that any boomer selling will occur gradually over a long period of time, are two reasons why Ms. Sonders isn't worried about the impact aging boomers will have on the market.

John Milne, whose JKMilne Asset Management specializes in bonds, expects investors who actively manage their portfolios will be reluctant to reduce their stock holdings in retirement because they expect to live longer and need the fatter returns. Yet recent events, including Wall Street's recent swoon and rising interest rates, could make them reconsider.

"You have a generation right now, people in their 60s, that saw the events of 1987 and 2000, and they'll be very reluctant to be very aggressive in the equity market again," says Mr. Milne, whose firm is based at Station Square.

The oldest boomers are four decades removed from their misspent youth. What they'll do with their stocks at retirement remains to be seen. Fears of an orgy of selling appear to be overblown, but with this group, you never know.

It comes down to whether you can trust anyone over 60.