Trailing Twelve Months (TTM) Definition: Trailing twelve months (TTM) is a company’s financial results for its four most recent reported quarters added together, regardless of when its fiscal year ends. It rolls forward every time a new quarter is published, replacing the oldest quarter with the newest one. Analysts use TTM revenue, earnings and cash flow to get a full-year picture that is never more than about three months out of date.
What Is Trailing Twelve Months?
Annual reports age quickly. A company whose fiscal year ends in December publishes its annual numbers in February, and by November those figures describe a period that ended almost a year earlier. Three newer quarters have been reported since, but the annual total ignores them.
Trailing twelve months fixes that by always using the latest full year of data. Instead of waiting for the next annual report, you add up the four most recent quarters. In November, that means the fourth quarter of last year plus the first three quarters of this fiscal year, which together still cover exactly 12 months.
Because the window is always a full year, TTM keeps one advantage of annual data: seasonal swings cancel out. A toy retailer’s huge holiday quarter and its quiet spring quarter both stay inside the total, so TTM figures can be compared from one quarter to the next without adjusting for the calendar.
How to Calculate TTM
There are two equivalent methods. The first adds the four latest quarterly figures. The second takes the last full fiscal year, adds the year-to-date figure for the current year and subtracts the same year-to-date period from the prior year.
Suppose a company reported annual revenue of $400 million for its fiscal year. Nine months into the next year, it has sold $330 million, against $290 million in the same nine months a year earlier. TTM revenue is $400 million + $330 million − $290 million = $440 million, a figure that already reflects the stronger recent trend.
Now apply the same idea to earnings per share. If the last four quarters produced $0.50, $0.55, $0.60 and $0.65, TTM EPS is $2.30. At a $46 share price, the TTM P/E ratio is 20.
When the company reports a new quarter of $0.70, the oldest $0.50 drops out and TTM EPS rises to $2.50. With the share price unchanged at $46, the P/E falls to about 18.4. Nothing happened to the stock, yet it looks cheaper, simply because the earnings window moved forward by one quarter.
Do not confuse TTM with an annualised figure. Annualising multiplies a single quarter by four, so a retailer that earns most of its profit in the holiday quarter would look several times more profitable than it is if you annualised that quarter alone. TTM avoids the problem because every season is counted exactly once.
TTM vs. Fiscal Year vs. Forward Figures
| TTM | Fiscal year | Forward (next 12 months) | |
|---|---|---|---|
| Period | Last four reported quarters | Company’s official 12-month year | Next four quarters |
| Source | Reported results | Reported and audited results | Analyst or company forecasts |
| Updates | Every quarter | Once a year | Whenever estimates change |
| Main weakness | Looks backward | Can be up to a year old | Can be wrong |
Most financial websites quote P/E ratios on a TTM basis unless they label them forward. Checking which one you are reading matters, because the two can differ widely for a company whose profits are rising or falling fast.
Why Is TTM Important for Traders?
TTM gives you the most recent full-year view built only from reported numbers. It is the default basis for valuation ratios, for trailing dividend yield and for revenue growth comparisons that span more than one quarter. Lenders use it too: loan agreements often cap debt at a multiple of last-twelve-months EBITDA, so one weak quarter can push a borrower toward a covenant breach.
Its main weakness is that it looks backward at turning points. Imagine an airline that earned $1 per share in each of three quarters and then lost $3 in a quarter hit by a fuel price shock. TTM EPS is zero, and the P/E becomes meaningless, even if the next quarter returns to normal. The reverse also happens: a cyclical company at its peak shows a low TTM P/E just before profits fall.
One-off items cause similar distortions. A large asset sale or write-down stays in the TTM total for four quarters, and an acquisition adds only part of a year of the new business. Analysts often adjust for these items or use pro forma TTM figures, which restate the period as if the deal had closed at its start.
Watch the calendars as well. Two retailers with fiscal years ending in January and in September report on different schedules, so their TTM windows in the same month can be offset by several months. Comparing them side by side assumes nothing important changed in the months one window covers and the other misses.
Key Takeaways
- TTM adds up a company’s four most recent reported quarters, giving a full-year figure that updates every quarter.
- It can be calculated as the last fiscal year plus current year-to-date results minus the prior year’s matching year-to-date period.
- Because the window always covers 12 months, seasonal patterns cancel out and TTM figures stay comparable from quarter to quarter.
- Valuation ratios such as P/E usually use TTM earnings, so they can change when a new quarter is reported even if the share price does not.
- TTM looks backward, so it misleads at turning points and when one-off gains, losses or acquisitions sit inside the window.
Is TTM the same as LTM?
Yes. Last twelve months (LTM) and trailing twelve months describe the same window, and LTM is the label more often used in loan agreements and acquisition documents.
Why does a stock's P/E change when its price has not moved?
TTM earnings update every quarter. When a new quarter replaces an older and weaker one, the denominator rises and the P/E falls even if the share price is unchanged.
Should I use TTM or forward figures?
Use both. TTM numbers are reported facts but look backward, while forward numbers rely on forecasts that can be wrong, and a large gap between the two tells you the market expects a sharp change.
