The stock, already down 80 percent from its 52-week high of $67.73, took another beating after JPMorgan analyst Kenneth Worthington said Lehman is facing "another difficult quarter." He follows similar projections from analysts at Merrill Lynch, Deutsche Bank, and Fox-Pitt.
Worthington, and others, believe that Lehman will purge its books of risky mortgage-backed securities when it reports next month.
"We believe the management wants to leave its mortgage troubles behind and restore confidence, which it can best accomplish by reducing its higher-risk credit exposure," Worthington said in a research note.
Also on Tuesday, Standard & Poor's kept its "Hold" recommendation on Lehman Brothers.
Lehman shares fell 10.1 percent to $13.52.