1. Nonperforming securities.
2. Highly speculative securities.
“Wall Street disdainfully regards most penny stocks as cats and dogs, a popular phrase in use since 1879 to describe low-priced, often worthless, speculative securities. The single word dog also means a worthless security, and the related pup meant a low-priced, inactive stock during the 1940s and 1950s.” Kathleen Odean, High Steppers, Fallen Angels, and Lollipops: Wall Street Slang 10 (1988).