Must-read article in yesterday’s WSJ:

The Hidden Costs of Mutual Funds

Portfolio managers can rack up steep expenses buying and selling securities, but that burden isn’t reflected in a fund’s standard expense ratio.

How much does it cost you to own a mutual fund? Probably a lot more than you think.

In selecting mutual funds, most investors know to check the expense ratio, the standard measure of how costly a fund is to own. U.S.-stock funds pay an average of 1.31% of assets each year to the portfolio manager and for other operating expenses, according to Morningstar Inc.

But that’s not the real bottom line. There are other costs, not reported in the expense ratio, related to the buying and selling of securities in the portfolio, and those expenses can make a fund two or three times as costly as advertised.

“These trading and transaction costs are very real,” says Stephen Horan, head of professional education content and private wealth at CFA Institute, a nonprofit association of investment professionals. “While it’s very important to look at that expense ratio, it’s just not going to capture” all of the costs, Mr. Horan says.

Read the entire article here. Morningstar’s estimates of the average fund expense ratio in the above is lower than the industry’s own estimates. I compare mutual fund costs to Spoke Fund® costs here. And email me to receive my article “Ten Things You Must Know Before Investing in Mutual Funds.”