An increasing number of investors are betting that General Motors may be forced to seek bankruptcy protection within the next six to 12 months.
The world's largest automaker is struggling to overcome slumping sales and the high cost of health care benefits for workers and retirees.
GM says it has no plans to declare bankruptcy.
But concerns about the automaker's future are showing up in the credit default swaps market. That's where investors effectively buy insurance protection against defaults.
Holders of GM debt who want to arrange a hedge against the risk that they won't be repaid are finding that the cost of buying the protection has risen dramatically in recent days.