When you open up your mutual-fund statements, do you find yourself muttering, "I could do better than this manager," or, "Why is my tax bill so big every year?"

Now, you can channel those frustrations into a new product that lets investors create stock portfolios or choose from a menu of ready-made portfolios.

Anyone can build a portfolio through a broker, of course, but the new product, called Foliofn (the f is for financial; the n is for the last letter in innovation) charges $295 per year, or $29.95 per month, to buy as many as 150 stocks. Buying that many stocks, even through a discount broker, would cost $4.95 to $29.95 per trade. At that price, you could easily pile up a tab of more than $295.

For that amount, investors can pick up to three folios of 50 stocks each.

The folio idea, created by Steve Wallman, a former Securities and Exchange Commission member, is a cross between a mutual fund and an online brokerage account.

As with a mutual fund, investors get a well-diversified portfolio without having to spend the thousands, even the hundreds of thousands of dollars, needed to buy all of those stocks. With Foliofn, you could buy $1,000 worth of a portfolio you create or select from one of the company's 80 ready-made folios.

As with an online brokerage account, you can trade stocks, and unlimited trading is free as long as you agree to have a trade executed at 10:15 a.m. or at 2:45 p.m. If you want to execute the trade at a specific time, it will cost $14.95 per trade. Processing trades just twice a day helps the company match customer orders and keep prices low. Orders can be placed at any time, however.

There are no account minimums at Foliofn, so investors who want to stake a small sum can. That might be useful for someone who wants to invest $1,000 or so in, say, biotechnology or aerospace stocks.

Normally, assembling such a portfolio would require several thousand dollars. Foliofn gets around that by divvying up shares among investors.

"What we'll do is, we'll give you fractional shares," said Nancy Smith, vice president of education at Foliofn in Merrifield, Va.

But at $295 a year, investing small amounts gets expensive.

Which brings up an important issue.

Foliofn is cheaper than creating a diversified portfolio through a broker, but it's not cheaper than most mutual funds for small investors. With the average stock mutual fund charging 1.23 percent in expenses, only investors with more than $24,000 in a fund would pay more than $295 in fees yearly.

Stick your money in an ultra-cheap index fund, and the costs are even harder to beat. With Vanguard's 500 Index fund, one of the cheapest at $1.80 per $1,000 invested, only investors with more than $164,000 would pay more than $295 in yearly fees.

But there are other advantages to Foliofn. By deciding when to buy and sell, you control when you pay taxes. With a mutual fund, investors pay taxes when the manager buys and sells. And because most managers are paid based on the total returns they produce, not on whether they are tax-efficient, fund investors can wind up with huge bills.

Many fund families, however, including Vanguard and T. Rowe Price, offer tax-efficient mutual funds that try to keep tax bills low. They may be a better option for smaller investors.

Russ Kinnel, who follows mutual funds for Morningstar Inc., the Chicago fund-tracking company, thinks the folio idea may be a hit if financial advisers and brokerages that offer mutual-fund supermarkets start offering it.

"There's potential there," he said. "It's a fairly involved, sophisticated tool. But I don't see a lot of people chucking their Schwab or Merrill Lynch accounts to go and do it."

Instead, he said, people likely would use folios to patch holes in their stock holdings. He cited an example of someone who owns a lot of stock in Cisco Systems Inc. but no other large growth companies. That person could choose a folio of, say, all the large growth companies in the Standard & Poor's 500 index except Cisco.

The ready-made portfolios Foliofn has constructed include a wide range of styles. Investors can buy a broad folio, such as 49 stocks from around the world. Other focuses are more narrow, such as the Ireland or NASCAR-sponsors folios. Some folios screen out tobacco stocks or include only companies with a high percentage of minorities on their boards of directors.

Foliofn's research department creates the portfolios based on various criteria, such as a stock's volatility relative to the S&P.

Foliofn, which started in May, won't say how many customers it has so far, but the idea is gaining momentum. On July 17, E-Trade, the online broker, announced plans to acquire eInvesting, which provides personalized portfolios. E-Trade says it plans to start selling its portfolio products by the end of the year.

No word on pricing yet, but Liat Rorer, vice president of asset gathering at E-Trade, said the product would be competitive.

"I think it's likely that customers will, with a portion of their assets, want to have brokerage assets as well as mutual-fund assets as well as these portfolios," Rorer said. "I actually believe we'll see investors using all three products, just as now you see an investor using both mutual funds and brokerage accounts today."

Charles Schwab, the largest discount broker, said it is considering a similar product but wants to gauge customer demand first. Another company, NetFolio, plans to offer a folio service for $195 yearly in the fall.

Although the pricing of Foliofn makes it most appropriate for people with a fair amount of money, some services cater to people who just want to buy a few shares of stock and hold them.

Buyandhold.com, for example, lets investors choose from 1,400 stocks and funds based on various indexes. The commission is $2.99 per trade. Foliofn would be a better buy for frequent traders unless they incur extra fees by trading outside the two daily windows.

Sharebuilder is a similar service. It charges $5 for one-time investments, and $2 for those who make regular monthly trades.