Series 55 A securities license entitling the holder to actively participate in equity trading. Investopedia Says: The Series 55 exam is administered by the NASD, covering topics such as OTC and NYSE trading practices, rules and regulations, and electronic trading systems. Related Terms: Broker NASD Series 11 Series 24 Series 26 Series 27 Series 3 Series 30 Series 31 Series 4 Series 6 Series 63 Series 65 Series 7 |