Young owners of individual retirement accounts (IRA) tend to invest more in equities and balanced funds (a mix of equities and bonds) than investors age 45 or older who favor bonds. And investments along gender lines are pretty similar. That's the takeaway from new analysis released today by the Employee Benefit Research Institute.

IRAs hold more than 25 percent of the nation's retirement assets. Much of this money started out as 401(k) plans through employers and were rolled over into IRAs when workers switched jobs.

I found the section on "extreme allocations" to be very interesting. According to the EBRI data, which contains information on 14.1 million accounts with assets totaling $732.9 billion, Roth IRA users are much more likely to have 90 percent or more of their assets in stocks than owners of other pre-tax IRA accounts.

Roth IRAs are funded with after-tax dollars, which appeals to investors who believe their own individual tax rate, or taxes in general, will increase by the time they access this retirement stash.

Other groups that are more likely to have the vast majority of their money in stock include investors with less than $10,000 saved and investors who are younger.

A couple possible explanations for these extremely aggressive allocations. Roths tend to be supplemental to 401(k) accounts because of the $5,000 annual contribution limit ($6,000 for those 50 or older). Often times, it is costly to allocate small chunks of change into various mutual funds, if the mutual fund company allows investments of $500 or $1,000 at all.

Many young people also subscribe to the idea that they can be incredibly aggressive because their money has decades weather the market ups and downs before it will be needed to live on. But the market downturn has tested investors' ability to withstand the stock market rollercoaster. This data is from 2008. My guess is we'll see some big shifts in allocations once EBRI releases 2009 data (the market hit bottom in March 2009), and even greater movement toward less risky investments in 2010.