"We're concerned that the cycle may be on its last legs, " says Bart Mosley, co-president of Trident Municipal Research in New York.

WSJ: Are High-Yield Munis Headed for a Fall?

Best Buy meanwhile, was supposed to be on its last legs, with only a buyout led by founder Richard Schulze looming as a potential lifeline.

FORBES: HP Paces Dow's Big Quarter, Leaves Caterpillar In The Dust