SuperMontage also abbreviated simply as SM is an integrated trading system used in an American stock exchange NASDAQ that was implemented in 2002. It features fully integrated public limit order book and market maker quotations, the ability to enter multiple quotes, anonymous ordering, five-level deep buy and sell interest and time-stamps on individual orders.
Test stock symbols
The SM system generally works behind the scenes, but on rare occasions it can be seen at work when a test symbol such as "ZVZZT" runs across the ticker.
NASDAQ strongly encourages firms to utilize the test securities for testing their production systems.
References
Supermontage Wikipedia(Text) CC BY-SA