A trade price that is lower than the immediately prior trade price. It constitutes a trade (tick) at a smaller price than the last reported price. For example, the last trade price for XYZ is 50.03 dollars and the previous trade price is 50.06 dollars. This company’s stock is said to be on a lower tick (downtick or minus tick) because the current price is higher by the previous one (in this specific case by 6 cents).