Whether Rupert Murdoch will be successful in his bold pursuit of Dow Jones & Co. is anybody’s guess. Despite his enormous success, his dogged determination to succeed in every personal and business outing and, his deep pockets, some Wall Street pros are already betting he’s a loser.

Indicative of this, some hedge funds sold Dow Jones short — a bet its price will fall — after his recent unsolicited $5 billion, or $60 a share, bid to buy the parent of the Wall Street Journal and Barron’s.

With Dow Jones trading at $55, a discount to the bid price, and the distinct possibility, some say, that Mr. Murdoch’s News Corp., the owner of the Fox News cable channel, might well sweeten the Dow Jones offer a bit, shorting the stock would seem awfully risky.

Not so, argues one hedge fund manager who recently sold Dow Jones short. “It’s a nondeal, speculation that may make for exciting reading in your local newspaper, but an event that’s just not going to happen,” the manager, who asked not to be identified, says.

His chief reasoning, he says, is the strong opposition of the controlling Bancroft family. It owns 64.2% of Dow Jones’s voting shares, which, he contends, will be a tough, if not impossible, nut to crack. Granted, the holdings are divided up among 38 family members, but when push comes to shove, his sense of it is the family will stick together, which, he says, seems to be the overriding view of his contacts at Barron’s and the Journal.

The manager also looks for politics to emerge as a major issue in the matter, with Democrats, especially liberals, putting all sorts of roadblocks in the way of such a deal because of Mr. Murdoch’s strong conservative leanings. Intervention by the Justice Department is also envisioned as a possibility because of the enormous concentration of editorial power that would end up in one man’s hands.

Likewise, the manager thinks any such deal, assuming it could be done, would grow whiskers before its completion. “At the earliest,” he says, “you’re looking at a transaction that would be at least a year away.”

The head of one of the city’s most successful arbitrage firms, who asked not to be identified, ridicules the shorting, describing it as “amateur night at Minsky’s.” He figures the 76-year-old Mr. Murdoch, whom he views as smart and resourceful, has about a 40% shot of pulling it off. “To short this man is not only a dumb bet, but sheer insanity,” he says.

Repeated efforts to reach Mr. Murdoch for comment were unsuccessful.

The hedge fund manager of Dow Jones also views his short sale as a good risk-reward play. If he’s wrong, he figures he’s at risk of maybe four or five points on the upside. And if he’s right, he looks for the stock, minus a deal, to collapse back to the mid-$30s, giving him the prospects of about a $20 windfall on the downside.

The president of TrimTabs Investment Research of Santa Rosa, Calif., Charles Biderman, a former Barron’s reporter, thinks a takeover of Dow Jones by Mr. Murdoch could help revitalize the firm by giving it vision and a strategic plan. Dow Jones, he says, is very competent at providing news coverage, but horrible at managing the business. He cites, as examples, its allowing a host of rivals to easily enter its surf, notably Bloomberg, Reuters, Thomson Financial, and CNBC.

A professor of economics at the University of Maryland, Peter Morici, made observations along similar lines. There’s nothing to say that Mr. Murdoch couldn’t do things more efficiently by having the Journal produce more product with its current staff or do it with less staff, he says. Critical of Dow Jones for its reaction to Mr. Murdoch’s offer, he says the Journal “seems to be in favor of democracy for everyone but themselves.”

The head of New York hedge fund Balestra Capital Partners, James Melcher, figures Mr. Murdoch will be rebuffed. “All signs suggest the Bancroft family will kill the deal,” he says. “And if it’s not going to sell out at this price, it’s unlikely to sell out to anyone.”

Mr. Melcher also views a short sale of Dow Jones as “a sensible strategy.” Figure, he says, a 50-50 chance of the deal happening. That suggests, he observes, the stock goes up between 10% and 15% if it happens and falls say 30% if it doesn’t. “That’s a damned good bet,” he says.

Years ago, I had lunch with Mr. Murdoch and his second wife. She boasted that her husband would become the most powerful press figure in the city, and said “No one would ever say no to him.” She was wrong.