The forces opposing two new movie futures trading [4] markets gathered powerful congressional allies Tuesday.

California Sens. Dianne Feinstein and Barbara Boxer are among a number of legislators filing separate letters to the Commodity Futures Trading Commission, calling for approval delays.

That regulating body is mulling two futures trading systems established by financial giant Cantor Fitzgerald and Media Derivatives, both based on the box-office performance of major motion pictures.

The commission is expected to make a decision later this month as to whether the trading systems can go live later.

Last week, a powerful coalition of Hollywood guilds and lobbying organizations, led by the Motion Picture Association of America and the Directors Guild of America, sent letters [5] to the commission, describing the trading systems as “legalized gambling” and calling for delays in the approval process.

This week, members of Congress stepped in, with Texas Republican Lamar Smith, Ranking Minority Member of the House Judiciary Committee also weighing in, along with Henry Waxman, chairman of the House Energy and Commcerce Committee, and Rep. Bob Goodlatte, R.-Va.

“We are writing to request that you delay approval of designated contract markets that intend to facilitate trading of ‘movie futures contracts,’" read a letter jointly signed by Boxer and Feinstein. “The film industry has raised serious questions about whether these proposed markets are consistent with the public interest as defined by the Commodity Exchange Act. The Commodity Futures Trading Commission should fully consider and address these concerns before it acts.”

You can read Feinstein and Boxer's letter to CFTC chairman Gary Gensler here [6].

For its part, Cantor Fitzgerald, which already operates the popular play-money-based Hollywood Stock Exchange, has spent four years and millions of dollars developing a futures index that’s based on the first four weeks of movie box-office performance.

Up to six months before the scheduled release of a film, traders – both institutional and Average Joe – would be able to bid on what they believe will be the movie’s performance after four weeks in theaters.

In Los Angeles Tuesday to "educate" studio officials on what he sees as a large-scale misunderstanding of the fundementals of futures trading, Cantor Exchange president Rich Jaycobs told TheWrap that, as far as he can tell, his company's new trading system is on track for a go or no-go decision from the CFTC on April 20, per schedule.

"I haven't heard anything to the contrary," he said. "There continues to be a lot of myths around these contracts, and we continue to try to educate the public. We just have to do a lot more of that, because right now, the hyperbole is intense."

Cantor officials are marketing their new service as a tool for the movie industry -- one that can be used to offset risk, as well as recoup lost upside. A producer who feels too overextended on a project, for example, might bid low, thus offsetting his risk if his film should fail.

Meanwhile, a stockholder for an exhibitor might feel that the theater chain doesn’t have enough engagements for an upcoming tentpole. He or she could then bid on the high side of the market and participate in profit opportunities that might otherwise be lost.

For their part, however, the MPAA and its constituents have expressed strong misgivings about such a trading system -- especially following a 2008 financial disaster on Wall Street that was largely based on “innovative” financial products. (Although, it should be noted that none of those products were of the futures trading variety.)

Key among studio concerns: Such systems could be gamed, since all or most data originates from the studios themselves.

“We’re not talking about wheat futures here, where you can go to the weather service and find out how much rain there was,” one studio executive told TheWrap.