The U.S. Supreme Court let stand a major insider-trading ruling that threatens at least 10 convictions and creates what the Obama administration calls a road map for securities fraud.

Rejecting an administration appeal without comment, the justices refused to consider reinstating the overturned convictions of hedge fund managers Todd Newman and Anthony Chiasson. Among those who may benefit are SAC Capital Advisors LP's Michael Steinberg, who is seeking to reverse his own conviction on similar grounds.

The rebuff is a blow to U.S. Attorney Preet Bharara, the New York prosecutor who had racked up more than 80 insider-trading convictions during a six-year attack on crooked fund managers, corporate insiders, and consultants. The high court's action came in a list of orders released on the first day of its new nine-month term.