STEP 1Quarterly results and two ways to compare
Waiting only for a one-year report card means waiting too long. That is why listed companies report their results every three months. The question is what you compare those three-month numbers against.
The report card that comes out every three months
As seen in Lesson 4, a listed company with a December fiscal year-end files a report each time Q1 (Jan–Mar), the first half (Jan–Jun) and Q3 (Jan–Sep) end, and files an annual report when the year ends. So investors can check a company's results four times a year. Quarterly results come out sooner and more often than annual results, so stock prices react to quarterly results more often than to annual ones.
Splitting Robin Bakery's (fictional) Year 3 revenue of KRW 12 billion into quarters gives KRW 2.7 billion in Q1, KRW 2.8 billion in Q2, KRW 2.9 billion in Q3 and KRW 3.6 billion in Q4. Q4 is especially large because Christmas and year-end cake orders pile up. Operating profit is also largest in Q4: KRW 300 million, KRW 320 million, KRW 330 million and KRW 550 million.
Quarter-over-quarter (QoQ) and year-over-year (YoY)
There are two ways to compare quarterly results. One is (QoQ), which compares with the immediately preceding quarter, and the other is (YoY), which compares with the same quarter a year earlier. The "15.6% decline" in today's opening question is QoQ. Comparing Year 3 Q1 revenue of KRW 2.7 billion with the immediately preceding quarter, Year 2 Q4, at KRW 3.2 billion gives −15.6%. But compared with the same Q1 a year earlier, at KRW 2.5 billion, it is +8.0%. With the same number, one comparison says "plunge" and the other says "growth."
As a running analogy, comparing a midsummer time with a midwinter time is QoQ, and comparing it with last summer's time is YoY. For a business where the seasons change results a lot, such as with the weather, you need to compare the same season to see whether it has really improved.
QoQ = this quarter ÷ previous quarter − 1 · YoY = this quarter ÷ same quarter last year − 1Robin Bakery (fictional) Year 3 Q1 revenue: QoQ 27 ÷ 32 − 1 = −15.6% · YoY 27 ÷ 25 − 1 = +8.0%
See it in a chart: the same quarter, a different story
Click the Year 3 quarterly bars. The buttons at the top let you switch the comparison method (QoQ, YoY) and the figure (revenue, operating profit). The pale bars are Year 2 and the dark bars are Year 3.
Year 3 Q1KRW 2.7 bn
Compared withKRW 2.5 bn
Change+8.0%
These are fictional company numbers. Year 2 quarterly revenue is KRW 2.5, 2.6, 2.7 and 3.2 billion (total KRW 11 billion), and operating profit is KRW 240, 260, 270 and 430 million (total KRW 1.2 billion). Year 3 quarterly revenue is KRW 2.7, 2.8, 2.9 and 3.6 billion (total KRW 12 billion), and operating profit is KRW 300, 320, 330 and 550 million (total KRW 1.5 billion).
Quick checkRobin Bakery's Year 3 Q4 revenue of KRW 3.6 billion is +24.1% QoQ. What is it YoY? Which number is closer to "real ability"?
YoY is +12.5%, and YoY is closer to real ability. Compared with last year's Q4 of KRW 3.2 billion, it is 36 ÷ 32 − 1 = 12.5%. The QoQ +24.1% is mixed with the seasonal effect of the year-end cake peak, which makes the ability look inflated.
STEP 2Seasonality and 3-month vs cumulative numbers
Surprisingly many companies are seasonal. And when you open a quarterly report, the same quarter shows up on two lines, which can be confusing. Let's sort out both.
Industries with seasonality
is the tendency for results to rise or fall repeatedly at the same time each year. Ice cream and air conditioners are concentrated in summer, heating, year-end gifts and cakes in winter, and travel and airlines in the holiday season. It can also arise from the timing of a company's spending. A company that bunches bonuses or advertising at year-end shows lower Q4 operating profit relative to revenue.
For a company with seasonality, QoQ numbers rise and fall in the same shape every year, so by themselves they carry little new information. So for such companies, use YoY as the default and use QoQ to check whether "it did better or worse than the usual seasonal pattern." However, if the same quarter a year ago was unusually bad, YoY can look greatly inflated, so you should also think about the .
"3 months" and "cumulative" in the quarterly report
If you open the income statement in a quarterly report, there are two lines of numbers for the same quarter. 3 months is the result for just those three months of the quarter, and is the result summed from the start of the fiscal year to the end of that quarter. In a Q3 report, "3 months" is Jul–Sep and "cumulative" is Jan–Sep. For comparison, the same period's 3-month and cumulative numbers from a year earlier are shown on the right. Below is part of a real quarterly report's consolidated income statement, redrawn with the same numbers.
2-2. Consolidated income statement (unit: KRW million) · screen reconstruction
| 57th term Q3 (2025) | 56th term Q3 (2024) |
|---|
| 3 months | Cumulative | 3 months | Cumulative |
|---|
| Revenue | 86,061,747 | 239,768,567 | 79,098,731 | 225,082,634 |
| Operating profit | 12,166,062 | 23,527,391 | 9,183,371 | 26,233,258 |
| Quarterly net income | 12,225,747 | 25,565,060 | 10,100,904 | 26,696,957 |
| Basic EPS (KRW) | 1,802 | 3,724 | 1,440 | 3,834 |
Source: FSS DART, Samsung Electronics quarterly report (filed Nov 14, 2025, rcpNo 20251114002447) III-2-2 consolidated income statement, checked 2026-10-08. The table is redrawn with the original numbers and is only a navigation example, not a stock recommendation.
In this table, Q3 three-month operating profit was KRW 12.17 trillion, up about 32% from KRW 9.18 trillion a year earlier. But the Jan–Sep cumulative figure of KRW 23.53 trillion is actually about 10% lower than KRW 26.23 trillion a year earlier. This is a pattern of a weak first half followed by a Q3 recovery. As you can see, 3 months shows "the current pace" and cumulative shows "progress for the whole year."
Q4 numbers are found by subtraction
There is no separate report for Q4 alone, because once Q4 ends, the annual report shows the whole year. So are calculated as annual results − Q3 cumulative results. Companies often state Q4 numbers separately in preliminary earnings filings or earnings presentations, but the principle is the same.
Common misconceptions
- "If it fell from the previous quarter, results have worsened?"
- A seasonal company falls in the same quarter every year. Check YoY, the comparison with the same quarter last year, first.
- "Cumulative results fell, so it is bad now too?"
- As in the real case above, even if the cumulative figure fell, the most recent three months can improve a lot. Cumulative is progress; 3 months is pace.
- "YoY grew a lot, so it is definitely a good sign?"
- If the same quarter a year ago was unusually bad, the base effect makes the number look inflated. Compare with two years ago too, or look at the trend over several quarters.
Quick checkRobin Bakery's (fictional) Year 3 cumulative Q1–Q3 operating profit is KRW 950 million, and annual operating profit is KRW 1.5 billion. What is Q4 operating profit?
It is KRW 550 million. KRW 1.5 billion − KRW 950 million (300 + 320 + 330 million) = KRW 550 million. Q4 alone is more than a third of the year's operating profit, so this company's Q4 results largely decide the year's grade.
STEP 3Reading preliminary earnings and consensus
A quarterly report comes out within 45 days after the quarter ends, but big companies announce rough numbers much earlier. The day the stock price moves a lot is usually this day.
Preliminary earnings: the numbers announced first
is a disclosure in which a company announces key figures such as revenue and operating profit before it finishes closing its books. It is posted on the exchange disclosure system (KIND) and DART under names like "Consolidated Operating (Preliminary) Results (Fair Disclosure)." Because these are numbers before the external auditor's audit or , they can differ slightly from the quarterly and annual report figures that come later. For example, in the Q3 2024 case below, preliminary operating profit was announced as KRW 9.1 trillion, and the final figure in the quarterly report was KRW 9.18 trillion.
The gap from expectations, not the number
In Learn (Economics) Lesson 20, you learned that the market reacts to the gap from expectations rather than the indicator number itself. Corporate earnings are the same. The average of the earnings forecasts published by brokerage analysts is called the ; if the actual number is well above consensus, it is an , and if it is well below, it is called an earnings shock. If good results were already expected and reflected in the stock price, even large YoY growth is just "as expected."
| Announcement | Preliminary operating profit | Comparison | Market interpretation |
|---|
Oct 8, 2026
Q3 2026 | KRW 107.4 trillion | YoY +782.5% (KRW 12.17 trillion)
QoQ +20.0% (KRW 89.49 trillion)
Consensus KRW 105.55 trillion | About 1.8% above consensus, so "in line." Revenue of KRW 195 trillion was about 2.7% below expectations (KRW 200.4 trillion) |
Oct 8, 2024
Q3 2024 | KRW 9.1 trillion | Final figure in the quarterly report: KRW 9.18 trillion | Fell short of market expectations, and the head of the semiconductor division unusually issued an apology |
Sources: Yonhap Infomax, "Samsung Electronics Q3 operating profit KRW 107.4 trillion, in line with consensus" (2026-10-08; consensus based on Yonhap Infomax's composite consensus), Yonhap News (2026-10-08), Daum News and Green Economy News coverage (2024-10-08), DART quarterly report (rcpNo 20251114002447). Consensus differs by the compiling institution and the date. For example, the FnGuide compilation for the same quarter was KRW 106.9 trillion as of Oct 4 (Hankyoreh). The cases are to show how to read, and are not stock recommendations.
In the first case, YoY +782.5% is a very large number, but because the market had already expected the KRW 105–107 trillion range, it was read as "in line," not a "surprise." Conversely, because the same quarter a year earlier was very low, there was also a base effect that made YoY look inflated. The second case is one where profit grew a lot from a year earlier yet fell short of expectations and disappointed. Even the same "quarterly result" can mean the opposite depending on what it is compared against.
Finding it yourself on DART: the order for reading quarterly results
- 1When the quarter ends, check the scheduled announcement date on the earnings calendar, and on the day, look at revenue and operating profit in the preliminary earnings disclosure on KIND and DART.
- 2Compare with the consensus reported in the news the same day to judge whether it is a surprise, in line, or a shock.
- 3In the quarterly report that comes out within 45 days, check 3 months (YoY) and cumulative (this year's progress) in III. Financial Matters → Consolidated income statement.
- 4Find Q4 by subtracting Q3 cumulative from the annual figures in the annual report.
How to use it in investing
| When you see numbers like this | Try reading them like this |
|---|
| An article saying "revenue plunged quarter over quarter" | First check whether it is a seasonal industry and what the year-over-year (YoY) change is |
| "Up several hundred percent year over year" | Check whether the number from a year earlier was unusually low (base effect) and how far it differs from consensus |
| Preliminary earnings came in well above consensus | Check from the company's explanation and the quarterly report whether it was one-off or whether there is reason for it to continue next quarter |
| Cumulative results are far short of the annual outlook | Distinguish whether there is seasonality that bunches results into Q4, or a risk that the annual outlook will be lowered |
This is not always the case. Quarterly numbers can swing with one-off costs, exchange rates and the timing of accounting treatment. Look at the YoY trend over several quarters rather than a single quarter. This lesson does not recommend buying or selling any particular stock.
Quick checkA company's preliminary operating profit rose 50% from a year earlier, but consensus was for a 70% increase. How is the market likely to take this result?
It is likely to be taken as disappointing results (leaning toward an earnings shock). 50% growth is good in itself, but if the market had expected 70% growth and priced it in, the disappointment is as big as the shortfall. That is why on earnings day you should look at the gap from consensus along with YoY.