Trend analysis is a technique of financial statement analysis that examines how individual figures, such as sales, expenses, net income, receivables or inventory, change over a series of periods, usually three to ten years. By looking at the direction and speed of change rather than a single year's result, analysts can see whether a business is growing, stagnating or deteriorating, and whether different parts of the business are moving in step.
Trend analysis is closely related to horizontal analysis. Horizontal analysis typically compares two periods in dollars and percentages, as in comparative financial statements. Trend analysis extends the same idea over many periods, most often by expressing each year's figure as a percentage of a chosen base year, known as trend percentages or index numbers.
Calculating trend percentages
An early year is chosen as the base and set at 100. Each later year is expressed relative to it:
Here is the figure for the year being analyzed and is the same item in the base year. The base year should be a reasonably normal year; using an unusually weak or strong year distorts every later index.
Worked example
A home furnishings retailer reports the following, in thousands of dollars:
| Item | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|
| Net sales | $40,000 | $44,000 | $49,200 | $52,000 |
| Trend index | 100 | 110 | 123 | 130 |
| Cost of goods sold | $24,000 | $27,100 | $31,200 | $34,300 |
| Trend index | 100 | 113 | 130 | 143 |
| Accounts receivable | $3,000 | $3,600 | $4,500 | $5,400 |
| Trend index | 100 | 120 | 150 | 180 |
Sales grew 30 percent over three years, but cost of goods sold grew 43 percent, so the gross margin has narrowed from 40 percent to about 34 percent. Receivables grew 80 percent, far faster than sales, which suggests customers are taking longer to pay or that credit terms have been loosened. Neither problem is obvious from any single year's statements. The compound annual growth rate of sales over the period, about 9.1 percent, provides a single summary figure for the growth trend.
Uses of trend analysis
- Investors use it to judge whether growth in net sales and profits is sustainable and to spot turning points.
- Lenders look for deteriorating trends in liquidity, leverage and coverage ratios before problems become severe.
- Managers compare trends in costs with trends in activity to find areas where expenses are growing faster than the business.
- Auditors use trends as part of analytical procedures, investigating figures that break from established patterns, which can point to errors or misstatement.
- Ratios themselves can be trended, for example tracking gross profit percentage or days sales outstanding year by year.
Limitations
Trend analysis compares numbers prepared under accounting policies that may have changed over the period, for example through new revenue or lease standards, so restated figures should be used where available. Inflation makes nominal growth look stronger than real growth; analysts may deflate figures using a price index such as the consumer price index. Acquisitions and disposals can create jumps that do not reflect underlying performance. Percentages based on very small base amounts can produce huge, misleading changes. Finally, past trends do not guarantee future results, so trend analysis is best combined with vertical analysis, common-size statements such as the common-size income statement, ratio analysis and comparisons with competitors.