NEW YORK (MainStreet) -- There's a school of thought among Wall Street professionals that too many Baby Boomers are playing fast and loose with their retirement portfolios, particular amid fears they'll outlive their assets. Exhibit "A' this week is Fidelity Investments, and its quarterly retirement savings analysis of U.S. retirement accounts.

The report shows that many Boomers are "top heavy on stocks" in their retirement plan investment allocation, which puts their retirement funds at risk if the stock market declines, Fidelity reports. "Many older 401(k) account holders, including Baby Boomers close to retirement age, had stock allocations higher than those recommended for their age group," Fidelity reports. "18% of people 50-54 had a stock allocation at least 10 percentage points or higher than recommended, and for people ages 55-59, that figure increased to 27%."

One standard rule of thumb for asset allocation is to subtract your age from 120 to determine what percentage of your portfolio to put in stocks. If you are 50, that would mean 70% in stocks. But some are throwing caution to the wind: 11% of retirement savers in the 50-54 age group had 100% of their portfolios in stocks, according to Fidelity, as did 10% of the 55-59 demographic.

That's a recipe that could spell disaster for some Boomers. "One thing we learned from the last recession is that having too much stock, based on your target retirement age, in your retirement account can expose your savings to unnecessary risk - it's the hidden danger that many workers are unaware of," says Jim MacDonald, president of workplace investing at Fidelity Investments. "This is especially true among workers nearing retirement who should be taking steps to protect what they've worked so hard to save."

McDonald strongly advises retirement savers to regularly track their portfolio's asset allocation levels to "make sure your allocation stays on track."

Other retirement planning experts agree, saying that a market downturn is "inevitable."

"If retirees haven't rebalanced over the past six years during the bull market, then it's very possible that they could be relying too heavily on equities," says Christopher Cannon, a wealth manager at RetireRightPittsburgh in Pittsburgh, Pa. "Now would be an ideal time to revisit their allocation and ensure they are comfortable with the level of risk they are taking for the inevitable market pull back. However if they are comfortable with their allocation and understand the risks, hedging slightly towards equities right now might not be the worst idea."

Lena Haas, senior vice president of retirement, investing and savings at E*TRADE Financial, advises near-retirees to diversify across and within asset classes. "That will help reduce risk," Haas says. "Fortunately, today there are many mutual funds and ETFs that offer a high level of diversification, streamlining the investing process and eliminating the need to identify all the various regions, markets and asset classes yourself."

Additionally, always keep your eyes on the prize, she says. "Take a focus on long-term goals: consider a core-satellite investing approach wherein a portion - usually 10-to-40% - of a portfolio is devoted to specific sectors like emerging markets, keeping the remainder of the portfolio well-diversified across sectors and assets, mapped to investing objectives, time frame and risk tolerance," Haas says. "This can help take advantage of timely opportunities while still managing risk and remaining aligned with long-term goals."

Not everyone, however, is on board with the "top heavy stock philosophy. "As a Baby Boomer and a registered investment adviser, I can tell you first hand it's more likely most Baby Boomers have too little invested in stocks than too much," says Christopher Carosa, president of Carosa Stanton Asset Management, LLC, in Mendon, N.Y. "With life expectancies now moving into the 80s and, in quite a few cases, the 90s, retirement assets still need to be invested for the long-term - even if you're retired."

That being said, the issue of timing the market is always a tempting one, yet one that's rarely successful, Carosa adds.

"It's better to set aside, depending on your personal situation, two to five years of expenses into 'risk free' assets, even mean money markets that yield close to nothing, and leave the rest in long-term stock investments," Carosa says. 

As always with retirement investing, prudence should prevail. Sit down with a financial professional and chart out a course for retirement that maximizes a decent retirement income, and one that keeps risk at bay -- even if that might mean culling a few stocks from the herd in your portfolio.