a tick is a measure of the minimum upward or downward movement in the price of a security a tick can also refer to the change in the price of a security from one trade to the next since 2001 when the securities and exchange commission sec required all stock markets to convert to decimals the minimum tick size for stocks trading above 1 has been one cent 1
understanding a ticka tick represents the standard upon which the price of a security may fluctuate the tick provides a specific price increment reflected in the local currency associated with the market in which the security trades by which the overall price can change 3before april 2001 the minimum tick size was one sixteenth of a dollar meaning a stock could only move in increments of 0 0625 4 while the introduction of decimalization has benefited investors through much narrower bid ask spreads and better price discovery it has also made market making a less profitable and riskier activity 