Trend
How do you tell whether a market's moves add up to a real direction, not just one good week?
In plain words
A trend is a direction that persists across several periods, so the sequence of rises and falls, not one single result, points the same way. Traders confirm it by looking at several consecutive periods, the size of the moves, and where prices close within each period's range.
Why it matters
Most risk is taken on the assumption that the recent direction will continue. Reading one large period as a trend, or a genuine trend as a single outlier, changes how large a position can safely be and how far a protective stop should sit from the entry.
In a real week: BTC, week of 10 June 2019
In the week of 10 June 2019, BTC rose 17.38%, a result in the 91st percentile of its 69 weeks of history. It was not a first move: the prior four weeks returned 16.94%, 5.73%, 1.32% and -12.58%, so three were up and one was down. Volume ran above its prior 12-week average, the close landed in the upper third of the week's range, and the price finished 3.47% below its 52-week high. Several of these readings together, rather than the single week's gain, describe an established direction.
A common mistake
Calling a trend from one large period. A single strong week with no supporting sequence can reverse without warning, leaving the direction unconfirmed.