Trend

Look for the overall trend as well as short-term fluctuations. A generally rising series can still contain individual falls. A peak is a local or overall high point, while a trough is a low point.

A time-series graph can show rises, falls, peaks, troughs and an overall trend. In the illustrative sales data, sales fluctuate: they fall from February to March and from May to June. Nevertheless, the later figures are generally higher than the earlier ones, so the overall trend is upward.

First, look for its overall trend: is the quantity generally increasing, decreasing or staying roughly steady? Then look for shorter-term patterns. In the illustrative graph, profits are higher in each quarter of year 2 than in the matching quarter of year 1, so the overall trend is upward.