CHICAGO--May 21--Gambling regulators can learn a lot from the way the government polices trading in stocks and commodities, experts on both markets testified Wednesday.

Just as issuers of securities are required to disclose risks, casinos could be required to disclose the odds for all their games, suggested David Ruder, a former chairman of the Securities and Exchange Commission.  Advertising should also be regulated more, he said, to prevent casinos from advertising to those who lack the financial sophistication to understand the risks or who are unable to withstand a loss.

Ruder testified before the National Gambling Impact Study Commission, which is meeting in Chicago this week. It's the third in a series of six regional meetings that the commission will hold.

Kay Coles James, dean of the Robertson School of Government at Regent University in Virginia Beach, Va., and an activist in conservative causes, is the chairwoman of the Commission. She said the group will report its findings to federal, state and Native American governments in June 1999.

Donald Sandidge, the Mayor of Alton, told the commission that the Alton Belle "is a major asset that would be difficult to replace." Since the Belle opened in September 1991, he said, Alton has received $34 million in gaming taxes.

Alton B. Harris, a Chicago lawyer and an expert on commodities, told the commission that a casino bet is very similar to a commodities contract.    "When one gambles, one enters into a contract with someone that (for example) if seven turns up on a pair of dice the first time you roll, you will be paid," Harris said.

With commodities, the contract is that if a certain price is reached, say for corn, one party will pay the other.

"The similarities between the commodities markets and gambling are so close," Harris said, "that in the statute regulating the commodities market, there is a specific provision pre-empting state law." Otherwise, commodities activities might be subject to state prohibitions against gambling, he said.

Although people often compare gambling to the stock market, Harris said, there is a difference. Buyers of stocks or bonds are getting something of value -- an interest in the issuing company. Futures contracts on commodities offer a better analogy, he said, because they are merely contracts.

The Commission heard sometimes-emotional testimony Wednesday from pro- and anti-casino witnesses. The mayors of five Midwestern cities sang the praises of riverboat casinos, saying their cities have been revitalized by the tax revenue and increased development spurred by the boats.

Sandidge and his counterparts said there have been virtually no problems associated with the casinos. But other witnesses blasted the gambling industry.

Monsignor John J. Egan of Chicago spoke of "terrorized" gamblers "leaving babies to bake in closed-up cars. Dropping Social Security checks into slots, quarter by quarter. Betting the rent."

Rev. Tom Grey of the National Coalition Against Legalized Gambling  said, "Gambling's crapped out in the Midwest." He predicted that Missouri voters would defeat a November ballot proposition to legalize "boat in a moat" operations.

Even before the commission's hearings started Wednesday morning at a state office building here, the two sides were busy. Industry groups and officials from riverboat casino cities were telling their story in the lobby, while anti-casino activists prayed "against this wickedness" outside the building's entrance.

The commission, created by Congress in 1996, has been highly controversial from the start. The casino industry fears a witch hunt that could lead to federal regulation, and anti-gambling forces fear a whitewash that will result in no changes.