et's suppose that back in 1993 you were looking for an all-weather mutual fund. You picked Fidelity Asset Manager based on its soothing name and stunning record. Wouldn't you have been surprised the following year when the fund took a big hit in the Mexican peso crisis?

Back then, you probably couldn't have discovered that this supposedly conservative fund had moved into Mexican bonds, which tanked along with the peso. Today, though, you can learn much more about where their mutual fund managers are putting your money - thanks to some new online services.

In the fall of 1997, for example, Foster Freiss moved the bulk of the assets of Brandywine, his high-octane growth fund, into cash. The move was widely reported in the press.

Even if it had not been, however, investors could have discovered it by using the "X-ray" function on Morningstar.Net, the online publication of Morningstar Mutual Funds, the Chicago-based rating service.

Like other investing sites on the Web - including Microsoft Investor, - Morningstar shows where a fund's assets are invested - in stocks, bonds and cash. According to the latest data, Brandywine is invested 77.8 percent in cash. Brave man, that Freiss.

But not all Brandywine's shareholders applauded the bold move. Net redemptions in the fund are in the hundreds of millions. Recent performance has been anemic.

This is important stuff for mutual fund investors to monitor. Perhaps you don't need to know every single security in your fund's portfolio.

But there are some key things you should clock: How consistent is the manager in his approach? How concentrated is the fund? What are the sector weightings - both industry and regional?

"This helps you identify the risk you're taking," says Don Phillips, chief executive officer at Morningstar Mutual Funds. "You can't avoid risk. But you should be able to identify it."

Phillips tells the story of an investor he met at a recent mutual fund conference in Florida. She owned PBHG Growth and Fidelity Magellan and was looking for a third fund to provide diversification.

She'd done a lot of research and identified Seligman Communications as the best option. She wanted to know what Phillips thought of her choice.

He pointed out that Magellan had a 45 percent weighting in technology. PBHG had a 50 percent weighting in technology. And she was proposing to add a technology fund as diversification!

Read the prospectuses of the funds you own (which you can find on the funds' Web sites). You will at least know their stated objectives.

Don't be surprised to discover, however, that fund managers often have a lot of latitude.

Four or five years ago, most fund companies rewrote their prospectuses to give managers broad powers to do just about anything imaginable.

For instance, the changes in the bylaws at the Strong Funds included giving the manager the ability to buy real estate-related securities, trade commodity futures contracts, leverage as much as one-third of the funds' assets and borrow from or invest in other mutual funds.

That's quite a license. Strong argued it was simply following the leaders - companies like Fidelity Investments, T. Rowe Price & Associates and J.P. Morgan.

You can still learn something by reading the prospectus and the regular fund reports to see what the fund has done in the past.

"They make kind of an implicit contract - although not a legally binding one - to state what they've done in the past," says Cebra Graves, editor of Morningstar.Net.

For example, the prospectus no doubt permits the fund manager to use futures. "But do they use futures?" Graves asks. "Probably not. That's what you want to find out."

If you've done some research on funds like Third Avenue Value or FPA Capital - or Brandywine - you'll know you can expect them to hold some cash. "If you are surprised, you haven't done your homework," Graves says.

Look also to see what kind of securities the fund holds. For example, you might buy an index fund assuming that you're investing in the broad market. But there are many different market indexes, some that invest in large-cap stocks, some in small-cap and some in international.

One index might buy all the stocks in a market index. Another might buy just representative samplings. So you do want to know what you've bought. "Don't just assume that an index is an index," Graves says.

There's a debate now raging in the industry over how much information mutual funds should be required to disclose about their holdings and how often they should be required to do it. Funds are now required to disclose their entire portfolios twice a year. They have two months after the end of each six-month reporting period to make the disclosure. That means the information investors receive could be eight months old.

A further problem with this system is that not all funds operate on the same fiscal year. That makes it difficult for an investor to compare different funds. "It's very difficult to pick a point in time and see how one fund stacks up against another," Phillips says.

Still, the Web can give you a leg up. Start with the fund company's own Web site. Graves particularly likes Fidelity's Web site, because that company releases the top 10 holdings as well as the sector weightings and any major changes in portfolios each quarter.

Vanguard Group goes one better by listing the top 10 holdings every month, according to John Woerth, a Vanguard spokesman. T. Rowe Price & Associates lists the top 10 holdings two weeks following the end of each quarter and will provide the 25 largest holdings on request, says Steve Norwitz, a T. Rowe spokesman.

Most other fund companies provide similar information. Charles Schwab Online provides information about Schwab's own funds as well as OneSource funds and fund tools.

A few even offer daily disclosures. Check out Mosaic Funds.

New, improved tools are coming. Morningstar's premium service will allow investors to break out the top 25 names in a fund portfolio and look at year-to-date returns for each stock.

It will also show the portfolio's exposure to different regions, such as Asia and Europe, and to different industry sectors, such as technology or financials. What Graves would like to see is a tool measuring the value of the trades a manager makes. For example, it might compare the performance of a portfolio as it looked at the beginning of a particular period with the performance of the portfolio as it evolved.

That would let you see what value - if any - the manager added on his watch.

Clearly, there's much more that can be done to help investors understand their funds and to guide them in putting together a portfolio.

But the tools available now are much better than what we had five years ago. And making use of them can make you a much more successful investor.