Corporate America has scored a hat-trick in the US Supreme Court, winning a trio of big cases that could substantially reduce the amount of cripplingly costly investor litigation faced by any company that lists on US soil.

This was exactly what President George W. Bush wanted. Faced with growing concern about how litigation costs are burdening the competitiveness of US markets, he did what only a president can do to stop it: packed the country’s top court with business-friendly conservatives such as John Roberts, the new chief justice, a former corporate lawyer, and Samuel Alito, a hardline conservative who replaced the inconsistently pro-corporate Sandra Day O’Connor.

He created what amounts to a dream court for American business. So it is hardly surprising that the top court delivered another big win to business this week, ruling in Stoneridge v Scientific-Atlanta that banks, lawyers and accountants can often escape being sued by investors, even if they play a fairly big part in perpetrating a securities fraud. To be able to sue, investors must prove that they relied on the third parties to make their investment decisions. And that, normally, is very hard to do.

That may sound like the wrong result for investors. Certainly, the facts of the case were unsavoury: Charter Communications, a cable company, persuaded Scientific-Atlanta and another supplier to participate in sham transactions so Charter could deceive its investors.

That certainly sounds like behaviour that courts should punish – and indeed, they can: the Securities and Exchange Commission can sue third parties that scheme with companies to perpetrate fraud, and it can distribute the proceeds to wronged investors. The only issue in the Stoneridge case was: should private investors also be allowed to get in on the act, or should the task of suing third parties be left solely to professionals at the SEC?

It is not as though third parties that aid and abet fraud are getting off scot-free: the SEC can, and should, still pursue them. Third parties – including accountants that help cook the books – must not be allowed to escape liability. But nor should profit-driven lawyers be allowed to eat up the recoveries with huge trans­action fees.

Investor advocates, and their Democratic backers in Congress, have reacted to the ruling with howls of outrage. If Congress wants private investors (and their entrepreneurial lawyers) to sue third parties, it can pass a law that says so. In the meantime, that job is better left to the SEC.