trend analysis
Picture marking a child's height on a doorframe every birthday. No single mark means much, but the rising line of marks tells you whether growth is steady, speeding up, or stalling. Trend analysis does the same with a company's financial figures over many years: it tracks the direction and pace of change so you can see where the business is heading, not just where it stands today.
The usual method picks one year as the base, sets each of its figures to 100, and restates every later year as an index relative to that base. If sales were 200,000 in the base year (= 100) and 240,000 three years later, the index is 240,000 / 200,000 = 120, meaning sales are 20% above the base. Doing this for several lines over five or ten years reveals patterns a single comparison would miss — say, revenue climbing steadily to 130 while net income flattens at 102, hinting that costs are creeping up.
Trend analysis matters because business is a story told over time; lenders, investors, and managers watch trends to forecast and to catch trouble early. It is essentially horizontal analysis stretched across many periods. The caveats are real: trends assume the past predicts the future, which it often does not; inflation can make a 'rising' trend illusory; and a change in accounting methods or a single acquisition can bend the line in ways that have nothing to do with underlying performance.
Using 2021 as base (= 100), a company's sales index runs 100, 108, 119, 131 over four years, while its net income index runs 100, 101, 99, 96. Sales keep rising but profit is sliding — a divergence trend analysis exposes that any single year hides.
Indexing to a base year exposes sales and profit pulling apart.
A rising trend is not proof of future success; inflation, a method change, or one acquisition can bend the line without any real improvement underneath.