Uptick

One tick whose price is above the previous one. Its opposite is a downtick. Where a price repeats, convention borrows the direction of the last change that did occur, so a repeat following an uptick is described as a zero plus tick and a repeat following a downtick as a zero minus tick. The comparison is always against the immediately preceding print, never against the session's opening price or any other level, which is why a long sequence of upticks can occur inside a market that is falling on the day.

Tick direction is the raw material for several things read off the tape. Tick charts advance a bar after a set number of prints rather than after a period of time. Measures of buying and selling pressure are frequently built by counting upticks against downticks over a window. And in United States equity regulation the word names a rule: short sales were once permitted only on an uptick, that requirement was repealed, and it was later replaced by an alternative rule that restricts short selling in a security only after its price has fallen by a stated percentage from the previous close. The restriction is a market wide regulatory mechanism rather than anything a broker sets.

The trip is treating a tick sequence as a property of the market. It is a property of a feed. An exchange traded instrument has a consolidated record of prints, but a spot currency market is dealt over the counter with no central tape, so the ticks recorded are those one provider's feed published, at that provider's update rate, from the liquidity it saw. Two feeds can therefore disagree about the direction of the same instant, and any count built from tick direction inherits that disagreement.