Thailand's Most Volatile Industry Codes by Net Profit 2015-2025
In short
Construction of non-residential buildings, Thailand's largest industry code, posts the most volatile net profit of any sizeable industry code from 2015 to 2025. Its volatility score of 14.40 runs 39 times the typical qualifying code. The code lost 140.41 billion baht in 2017. It then rebounded to a record 28.60 billion baht profit in 2025. Eight other established codes, including steel, hotels and restaurants, swing between meaningful profit and meaningful loss the same way. Figures are current as of 14 Aug 2026.
Which industry code swings hardest between profit and loss?
Rank Thailand's sizeable industry codes by how much net profit moves from year to year, and one code stands well clear of the rest. Construction of non-residential buildings, TSIC code 41002, carries a volatility score of 14.40 across the eleven statement years from 2015 to 2025, according to the DBD registry (DBD, 2026). That score is the standard deviation of the code's annual net profit divided by its own average profit. A typical code among the 177 that cleared every filter for scale and meaningful profit carries a score of just 0.37. The leader therefore swings 39 times harder than a typical sizeable code. The same code is also Thailand's largest by company count. It carries 165,550 registered businesses. That works out to 8.32 percent of every company in the country. In 2017 the code posted a net loss of 140.41 billion baht. The year before, it had earned 25.55 billion baht. The year after, it swung back to a 22.69 billion baht profit. The strongest year in the entire span came last, 2025, with a record 28.60 billion baht in net profit. Across all eleven years the code still averages out to a net margin of just 0.49 percent. The wild swings mostly cancel each other out rather than building lasting wealth.
Volatility score by industry code, top 9
- 41002 Construction of non-residential buildings14
- 24109 Basic iron and steel, other9
- 82990 Other business support services7
- 33200 Installation of industrial machinery7
- 55101 Hotels and resort hotels4
- 46611 Wholesale of solid fuels4
- 77309 Renting and leasing of other machinery3
- 42909 Other civil engineering projects3
- 56101 Restaurants activities2
Figures in coefficient of variation of annual net profit, 2015 to 2025.
Two codes sit in construction, two in manufacturing, two in accommodation and food service, and two in administrative and support services. Thin margins and one off shocks run through most of the list.
The nine most volatile Thai industry codes by net profit
| Rank | TSIC code | Industry activity | Volatility score | Companies | Worst year: net result | Best year: net result |
|---|---|---|---|---|---|---|
| 1 | 41002 | Construction of non-residential buildings | 14 | 165,550 | 2017: -140.41bn baht | 2025: +28.60bn baht |
| 2 | 24109 | Manufacture of other basic iron and steel | 9 | 1,969 | 2015: -74.75bn baht | 2021: +20.42bn baht |
| 3 | 82990 | Other business support service activities | 7 | 14,194 | 2023: -72.89bn baht | 2024: +37.59bn baht |
| 4 | 33200 | Installation of industrial machinery and equipment | 7 | 5,541 | 2018: -43.51bn baht | 2023: +4.63bn baht |
| 5 | 55101 | Hotels and resort hotels | 4 | 19,664 | 2021: -65.07bn baht | 2025: +40.07bn baht |
| 6 | 46611 | Wholesale of solid fuels | 4 | 797 | 2024: -36.05bn baht | 2023: +26.05bn baht |
| 7 | 77309 | Renting and leasing of other machinery and equipment | 3 | 1,474 | 2023: -6.09bn baht | 2015: +5.11bn baht |
| 8 | 42909 | Construction of other civil engineering projects | 3 | 2,377 | 2022: -15.44bn baht | 2019: +1.05bn baht |
| 9 | 56101 | Restaurants activities | 2 | 51,204 | 2021: -10.01bn baht | 2025: +16.26bn baht |
Volatility score is the coefficient of variation of annual net profit across statement years 2015 to 2025, limited to codes with at least 500 companies and an average annual net profit of at least 1 billion baht. As of 14 Aug 2026.
Why a profit swing this size matters
A profit swing this size is not simply bad luck. Construction of non-residential buildings sits inside a broader construction sector that contracted 4.0 percent in the third quarter of 2025, according to the National Economic and Social Development Council (NESDC, 2025). That contraction snapped a streak of growth that had run for five straight quarters. Two of the other volatile codes on this list, hotels and restaurants, carry the scars of the pandemic years in their own worst year. Both bottomed out around 2021 before climbing to a record profit in 2025. A lender extending credit against one filed year's profit inside any of these nine codes is extending credit against a number that can move by more than double digit multiples of its own average within a single decade. A government forecasting corporate tax receipts from construction, hospitality or industrial installation faces the same problem. None of these are thin, marginal industries. Every code on this list carries at least 500 registered companies. Every one also averages at least 1 billion baht of annual net profit. The swings sit inside genuinely large parts of the economy, not a corner case that a bigger sample would smooth away.
Definitions
- TSIC code
- Thailand's 5 digit industry classification code, the finest level of detail the DBD registry publishes for a company's line of business, built on the international ISIC revision 4 standard.
- Coefficient of variation
- A volatility score equal to the standard deviation of a series divided by the absolute value of its mean. A score near zero means a series barely moves relative to its own average level. A high score means the year to year swings are large multiples of that average.
- Net profit
- Profit after all expenses, taxes and costs, summed across every company that filed a financial statement under a given industry code in a given statement year.
- Meaningful average profit level
- A floor of at least 1 billion baht of average annual net profit magnitude, applied so a code with a genuinely tiny average profit cannot produce an extreme volatility score purely from dividing by a number close to zero.
- Statement year
- The fiscal year a company's filed financial statement covers, recorded in the Thai Buddhist calendar in the source data and converted to the Gregorian year in this analysis.
- Qualifying universe
- The 177 TSIC codes that passed the minimum company count, full history and meaningful profit filters used to build this ranking, after two codes were excluded as data anomalies, one for an implausible average margin and one for a single year spike inconsistent with the rest of its own history.
Assumptions
- Only companies that filed a financial statement contribute to these figures.
- Codes were required to carry at least 500 registered companies, a full 11 years of statement history from 2015 to 2025, and an average annual net profit magnitude of at least 1 billion baht, a floor set specifically to keep a near zero average profit from inflating the volatility score.
- One code that otherwise cleared the filters, luggage and handbag manufacturing, TSIC 15121, was excluded for an implausible average margin beyond negative 1,000 percent, treated as a data anomaly rather than a real economic signal.
- A second code, activities of head offices and management consultancy, TSIC 69200, was excluded because one statement year showed net profit near 100 times every other year in its own history while every other year stayed positive, a pattern that looks like a data recording issue rather than a genuine swing between profit and loss.
- Statement year 2018 is a known registry coverage expansion year nationally. TSIC 33200's worst year falls in 2018, but its company count grew only about 6 percent that year, so the loss does not appear to be an artifact of new filers joining the code.
- The registry does not identify which company or companies drove any single year's profit or loss inside a code, so no company level cause is claimed beyond what company counts can rule out.
Methodology
Volatility is measured as the coefficient of variation, standard deviation divided by the absolute value of the mean, of a 5 digit TSIC code's total reported net profit across statement years 2015 through 2025, drawn from the DBD registry as of 14 August 2026. Codes are included only if they carry at least 500 registered companies, have a full 11 years of statement data across that window with no missing year, and average at least 1 billion baht of annual net profit in either direction, a floor chosen specifically to keep the score from exploding when average profit sits close to zero. Two codes that cleared the count and history filters were excluded as data anomalies rather than real economic signals. Luggage and handbag manufacturing, TSIC 15121, had an average margin beyond negative 1,000 percent. Activities of head offices and management consultancy, TSIC 69200, never posted a loss in any of the eleven years but jumped to a single year of net profit near 100 times its typical year, a spike inconsistent with a genuine profit to loss swing. Worst year and best year figures show each code's single lowest and highest annual net profit within the window, with the statement year converted from the Buddhist calendar to the Gregorian year.
How we verified this
- Recomputed the volatility score for TSIC 41002 as standard deviation 45,785,855,610.39 divided by the absolute mean net profit 3,180,619,122.06 across statement years 2015 to 2025, equal to 14.40, matching the reported top score.
- Recomputed the peak to trough net profit swing for TSIC 41002 as best year 28,601,785,053.83 minus worst year negative 140,410,893,203.47, equal to 169.01 billion baht.
- Recomputed the one year collapse for TSIC 41002 as the 2017 result of negative 140,410,893,203.47 minus the 2016 result of 25,547,239,570.95, a one year swing of negative 165.96 billion baht.
- Recomputed TSIC 41002's share of Thailand's registered companies as 165,550 divided by 1,989,709, equal to 8.32 percent.
- Recomputed the multiple between TSIC 41002's volatility score and the median score of the 177 code qualifying set, 14.40 divided by 0.369150, equal to 39.00, matching the value used in the prose.
- Recomputed the volatility score for TSIC 24109 as 23,858,522,031.73 divided by 2,617,518,189.29, equal to 9.11, confirming the second ranked score.
- Recomputed TSIC 41002's average net margin across the 11 years as mean net profit 3,180,619,122.06 divided by mean revenue 645,064,220,599.08, equal to 0.49 percent.
- Confirmed 177 codes cleared every filter, at least 500 registered companies, a full 11 years of statement data from 2015 to 2025, and an average annual net profit magnitude of at least 1 billion baht, after excluding TSIC 15121 for an implausible average margin and TSIC 69200 for a single year spike near 100 times its typical year with no loss year anywhere in the window.
- Cross checked the national totals of 1,989,709 registered companies and 3,290,602,409,386.72 baht in aggregate net profit against market_national_insight, matching the source table exactly.
References
- Department of Business Development. (2026). Registered juristic persons and financial statement aggregates. Ministry of Commerce, Thailand. https://www.dbd.go.th/
- National Economic and Social Development Council. (2025). Thai economic performance in Q3 of 2025 and the outlook for 2025 to 2026. Office of the Prime Minister, Thailand. https://www.nesdc.go.th/wordpress/wp-content/uploads/2025/11/05-PRESSENG-Q3-2568-Final-1.pdf
Frequently asked questions
Which Thai industry code has the most volatile net profit?
Construction of non-residential buildings, TSIC code 41002, with a volatility score of 14.40 across 2015 to 2025, 39 times the typical qualifying code.
How is net profit volatility measured here?
As the coefficient of variation, the standard deviation of a code's annual net profit divided by the absolute value of its own average profit, across statement years 2015 to 2025, limited to codes with at least 500 companies and a meaningful average profit level.
Why exclude codes with a tiny average profit?
A tiny average profit sits close to zero in the denominator of the volatility formula. That can inflate the score to an extreme level even when the underlying swings are modest in baht terms, the same distortion the data guide flags for return on assets and return on equity rankings.
Did the pandemic drive all of these swings?
Only for some codes. Hotels and restaurants both posted their worst year around 2021 and their best year in 2025, consistent with a pandemic hit and recovery. Construction's worst year was 2017 and steel's was 2015, both well before the pandemic, so no single cause explains every code on the list.
Cite this page
Chatpong L. (2026). Thailand's Most Volatile Industry Codes by Net Profit 2015-2025. Max Data Insights. https://maxdatathailand.com/insights/thailands-most-volatile-industry-codes-by-net-profit-2015-2025
Data & corrections
Download the data (CSV)Spot something off, or want to ask about the data? Email insights@maxsolutions.co.th. We publish corrections.
Written by
Chatpong L.Founder, Max Data, Max Solutions Co., Ltd.
Chatpong L. leads Max Data, a company-intelligence platform built on Thailand's official business registry. He writes about the structure of the Thai economy using primary registry data. His work covers company formation, industry concentration, and regional business activity.
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This page reports company-level and aggregate statistics only. It names no individuals and makes no claims about any person. Figures are provided for information and may be revised as source data updates.