Costecsys (355150) 🔎 In-depth
KOSDAQ · Price as of 2026-08-06 · Updated 2026-08-09
Costecsys supplies low-thermal-expansion, high-heat-dissipation materials and the semiconductor packages built from them. These parts draw heat away from power-handling chips while they operate and prevent the chips from cracking under the mismatch in thermal expansion between the chip and its substrate. Its main products are power-transistor packages for 5G communications and heat-dissipation components for next-generation power semiconductors such as SiC and GaN, so growth in the power-semiconductor market feeds directly into demand. After operating profit returned to the black in 2025, the company confirmed a swing to positive operating and net profit in Q1 2026, and a key driver is that its SiC heat-dissipation spacer has passed a global customer's mass-production qualification and entered full-scale supply. What stands out recently is that revenue has grown for three straight years and the Q1 swing to profit puts the company in an earnings-normalization inflection where forward P/B is lower than trailing, making it hard to read the elevated headline P/B and P/S simply as overvaluation. On the other side, a debt ratio of 151% and an interest coverage ratio below 1x mean interest costs could weigh more heavily if operating cash flow wobbles, and with the profit still resting on a single quarter its durability needs further confirmation.
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30-second brief
Pulled directly from the computed values below — not a separately written opinion.
What do the SourceComputedEstimateReading tags mean?
Source filings and exchange data · Computed calculated from public data · Estimate our own unverified projection · Reading drafted automatically, then rule-checked. See AI & Automation.
Core valuation metric
This stock's effective sub-sector is “Semiconductor Materials & Components” (Semiconductors & IT Components · Semiconductors), a type typically read first through forward P/E.
Semiconductor materials and components supply the inputs used in chip fabrication, and results move sharply ahead of and behind the chip investment cycle and customers' fab utilization. Because future earnings from recovering demand matter more than results already booked, the forward P/E — based on expected earnings — is the first lens.
Price against earnings alone becomes unstable when earnings swing. Reading it together with price against assets helps gauge the downside.
This note explains how each sector is typically valued and is educational context only, not investment advice.
At-a-glance assessment financial health · growth · profitability · valuation
- Operating profit barely covers the interest bill (interest coverage below 1x).
- The most recent full-year net result was a loss.
- Revenue rose 7.1% year over year, and the pace is slowing (3-year trend: rising).
- Most recent quarter (Q1 2026) revenue was 64.5% higher than a year earlier.
- ROE is -2.5% (total-net basis). It is above the sector average.
- Operating margin is 1.2%.
- P/E is hard to compute here, so this is read on P/B.
Ownership & governance As of 2025-12-31
Largest shareholder Han Tae-seong 26.93% (individual)
Controlling bloc incl. related parties 41.53%
With the controlling bloc holding 42%, the ownership structure is stable.
🔎 In-depth analysis Reading
Costecsys supplies low-thermal-expansion, high-heat-dissipation materials and the semiconductor packages made from them. These parts draw heat away from power-handling chips while they operate and keep the chip from cracking under the mismatch in thermal expansion between the chip and its substrate. Its core products are the ceramic, LCP and QFN packages used in 5G communication power transistors, along with heat-dissipation spacers and interposers for next-generation power semiconductors such as SiC (silicon carbide) and GaN (gallium nitride). Put simply, the company does not make the chip itself but the key components that support and cool the chip so it is not destroyed by heat. The more power an application handles — as with electric vehicles and 5G — the more important these parts become for reliably removing heat, so the expansion of the power-semiconductor market feeds directly into demand.
The latest close is ₩20,550 and the market capitalization is ₩160.2 billion. The price sits above its 20-day moving average (₩17,501) and below its 60-day moving average (₩29,555). Short-term and medium-term trends are diverging, so the direction is best read separately. The RSI (a supplementary indicator that gauges the strength of gains versus losses over the past 14 days on a 0-100 scale) is 52.1, a neutral level. The one-month change is +4.0%, the three-month change is -59.8%, and the position relative to the 52-week high is -65.1%. Relative strength versus the KOSDAQ is 91 (on a 1-99 scale, converted from returns against the index over the past year with more weight on recent performance; higher means stronger than the market). It is stronger than roughly 92% of all stocks. Over the past three months it lagged the index by 39.5%. Chart interpretation is best done alongside trading volume and the dates on which disclosures occur.
On the surface, P/B (how many times shareholders' equity the share price is) at 6.59x and P/S (how many times one year of revenue) at about 15.8x look high. But Costecsys is an earnings-inflection stock that has only just turned from losses to profit, so trailing metrics — which look only at the past year's results — do not fully capture where the company stands now. Because 2025 annual net profit was negative, trailing P/E (how many times one year of earnings the price is) cannot be computed, yet a forward P/E based on this year's earnings can be. By the same logic, forward P/B is 6.59x, lower than the trailing P/B of 9.30x. In other words, as equity and earnings normalize the valuation burden is moving lower, so this is not a stretch of price where the headline figures alone justify calling it expensive. On the financial side, a debt ratio (debt against equity) of 251% and an interest coverage ratio (how many times operating profit covers interest) below 1x mean operating profit alone is still stretched to cover interest in full — an item that can gradually ease if quarterly profit keeps widening.
Revenue rose for three straight years, from ₩11.5 billion in 2023 to ₩14.2 billion in 2024 and ₩15.2 billion in 2025 (a compound annual rate of about 14.8%), and operating profit turned positive at ₩184 million in 2025 after losses in 2023 and 2024. Net profit also narrowed its losses sharply each year, from -₩11.4 billion in 2023 to -₩1.8 billion in 2024 and -₩560 million in 2025. The decisive change came in Q1 2026: revenue of about ₩5.4 billion, up 64.5% year on year, with operating profit of about ₩1.13 billion and net profit of about ₩950 million, marking a clear entry into the black on a quarterly basis. Profitability climbed quickly enough that the single-quarter operating profit (₩1.13 billion) came to six times the full-year 2025 operating profit. Behind this jump is the fact that heat-dissipation parts for next-generation SiC and GaN power semiconductors passed a global customer's mass-production qualification and entered full-scale supply. Demand for power semiconductors is rising structurally across electric vehicles, renewables and industrial power supplies, and because the heat-dissipation materials Costecsys makes are added alongside more expensive chips, revenue and margin can improve together. This year's projected earnings running well above last year's annual figure reflects the fact that this mass-production ramp and pricing effect have actually shown up in quarterly results — which is also why the trailing P/E on last year's loss and the forward P/E on this year's earnings paint completely different pictures. That said, since this is only the first quarter in the black, the picture will sharpen as quarterly results confirm whether this rising trajectory continues past Q2.
After operating profit returned to the black in the 2025 annual report, the company held an investor briefing (IR) in April 2026 and, with the Q1 quarterly report in May, confirmed the swing to positive operating and net profit. On the business side, the key driver is that a heat-dissipation spacer for SiC power semiconductors passed a global customer's mass-production qualification and entered full-scale supply. On the finance and shareholding side, conversion rights on exchangeable bonds (EBs) were exercised and there was a change in a large-holding report, so — separate from the swing to profit — changes in share count and ownership structure are worth watching alongside.
Costecsys has clear strengths. On top of three straight years of revenue growth, both operating and net profit swung to the black in Q1 2026, putting the company at the start of a mass-production ramp in the structurally growing demand area of SiC and GaN heat-dissipation parts. The headline P/B of 9.30x and P/S of 15.8x look high, but — as seen in forward P/B falling to 7.68x, below trailing — this is an inflection where earnings and equity are normalizing, so it is hard to read simply as overvaluation. In short, this is a stock where profit has only just begun to catch up, and the valuation burden eases as quarterly results support it. The point to watch is the balance sheet. With a debt ratio of 151% and interest coverage below 1x, interest costs could grow if operating cash flow wobbles, and with the profit still resting on a single quarter its durability needs further confirmation. In sum, when mass-production supply and customer expansion are confirmed each quarter and the profit margin widens, the earnings inflection and the falling forward valuation reinforce each other and the stock reads strong; when the profit lasts only a quarter or two, or the financial burden comes back into focus, it reads weak.
🔎 Valuation vs peers Overvalued
Compared against companies whose business overlaps in semiconductor back-end processing (packaging and materials); Costecsys is more of a niche player than a general OSAT, specialized in heat-dissipation materials and packages for power semiconductors.
| Peer | P/E | P/B | ROE |
|---|---|---|---|
| Hana Micron | 53.89x | 4.36x | 23.42% |
| Nepes | 22.39x | 3.00x | 7.48% |
| Doosan Tesna | 851.47x | 2.90x | 0.35% |
| LB Semicon | — | 0.89x | -56.72% |
A P/B of 10.75x is higher than the peer set (Hana Micron 8.6, Nepes 6.77, Doosan Tesna 6.31), a clear premium versus back-end peers. This can be read as growth expectations for SiC and GaN heat-dissipation parts already priced in. That said, because 2025 net profit was negative, a trailing P/E on last year's confirmed results cannot be produced, and with the Q1 2026 profit only just confirmed the picture needs to be re-examined on this year's earnings (forward). On a forward basis there is room for earnings to normalize toward the level of some peers, but with the durability of the profit and the financial burden of a 251% debt ratio and sub-1x interest coverage both in play, it is hard to declare it cheap. It is reasonable to view the current price as a spot where growth expectations have run ahead.
Price history Close · MA20 · MA60
The latest close is ₩20,550 and the market capitalization is ₩160.2 billion. The price sits above its 20-day moving average (₩17,501) and below its 60-day moving average (₩29,555). Short-term and medium-term trends are diverging, so the direction is best read separately. The RSI (a supplementary indicator that gauges the strength of gains versus losses over the past 14 days on a 0-100 scale) is 52.1, a neutral level. The one-month change is +4.0%, the three-month change is -59.8%, and the position relative to the 52-week high is -65.1%. Relative strength versus the KOSDAQ is 91 (on a 1-99 scale, converted from returns against the index over the past year with more weight on recent performance; higher means stronger than the market). It is stronger than roughly 92% of all stocks. Over the past three months it lagged the index by 39.5%. Chart interpretation is best done alongside trading volume and the dates on which disclosures occur.
Relative performance stock vs index · start = 100
Excess return vs index · 3M -39.49% / 6M +101.98% / 12M +82.31%
Key metrics Computed vs sector median
Valuation
A net loss makes the P/E an unreliable valuation gauge. The P/B of 5.60x is above the sector median (1.63x).
Enterprise value (EV)
EV = market cap + net debt. It reflects cash and debt, so it captures the real cost of the whole business that market cap alone misses; lower multiples are cheaper relative to earnings or sales.
Profitability & financials
The operating margin is 1.2%. The debt ratio is 96.3%, so the financial structure is stable.
Growth FY2025 · annual report (separate)
| Item | 2023 | 2024 | 2025 | YoY |
|---|---|---|---|---|
| Revenue | $8.1M | $10.0M | $10.7M | +7.08% ↓ slower |
| Operating profit | -$927,225 | -$1.3M | $129,502 | — |
| Net profit | -$8.0M | -$1.3M | -$395,172 | — |
| 5-year | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|
| Revenue | — | — | $8.1M | $10.0M | $10.7M |
| Operating profit | — | — | -$927,225 | -$1.3M | $129,502 |
| Net profit | — | — | -$8.0M | -$1.3M | -$395,172 |
| Revenue CAGR | 2-yr avg 14.80% | ||||
Revenue rose 7.1% year over year (2023 ₩11.5 billion → 2024 ₩14.2 billion → 2025 ₩15.2 billion), and the three-year trend is 'rising'. That said, the pace of growth slowed from the prior year. Over the 3 years on record, revenue compound annual growth (CAGR) is 14.8%. The two-year revenue CAGR is 14.8%. In the most recent quarter (Q1 2026), revenue was 64.5% higher than the same period a year earlier.
Latest quarterly results Source Q1 2026 · vs year-ago
Technical indicators Computed
What stands out
- —
Points to watch
- Operating profit barely covers the interest bill (interest coverage below 1x).
- The most recent full-year net result was a loss.
- The most recent full year was a loss, so it is worth checking whether profitability recovers.
- Revenue rose 7.1% year over year, and the pace is slowing (3-year trend: rising).
- The price is high versus peers, so expectations already appear priced in.
Recent news & events searched · sourced
- 2026-05-15EarningsFiled the Q1 2026 quarterly report. Revenue of about ₩5.4 billion (+64.5% year on year), operating profit of about ₩1.13 billion and net profit of about ₩950 million, a swing to quarterly profit.Short term: the confirmed swing to profit lifts earnings expectations. Medium term: the level of earnings hinges on whether mass production ramps in earnest. Source
- 2026-04-13IRHeld an investor briefing (IR), explaining directly its business progress and the direction of its power-semiconductor heat-dissipation parts business.Short term: improves business visibility. Medium term: a reference point for checking plans to expand customers and products. Source
- 2026-03-18EarningsFiled the 2025 annual report. Revenue of ₩15.2 billion (+7.1%) and operating profit of ₩184 million turned positive, though net profit was -₩560 million, a narrowed loss.Short term: confirms the swing to operating profit. Medium term: whether net profit settles into the black is the point to watch. Source
- 2026-03-16UpdateExercise of conversion rights on the second exchangeable bond. Possible change in share count and ownership structure from the exchange.Short term: a potential source of increased share count (dilution). Medium term: warrants monitoring of the financial structure and shares outstanding. Source
- 2026-05-28FilingFiled a large-holding report (simplified form). Reports a change in holdings by a major shareholder.Short term: a signal of change in supply-demand and ownership structure. Medium term: material for checking governance and free float. Source
Figure cross-check computed ↔ external
Recent filings Source
- 2026-05-28OwnershipOwnership-change filing
- 2026-05-15PeriodicQuarterly report
- 2026-05-14OwnershipOfficers'/major-shareholders' holdings report
- 2026-04-13Disclosure
- 2026-03-27Disclosure
- 2026-03-26Shareholders' meeting notice
- 2026-03-18PeriodicAnnual business report
- 2026-03-18Audit report
- 2026-03-16Disclosure
- 2026-03-03Disclosure
- 2026-03-03Shareholders' meeting notice
- 2026-02-27Disclosure
📖 Plain-language glossary — expand if you are new to this
- P/E
- How many times a year's net profit the price is worth (lower is cheaper relative to earnings). The P/E here is on trailing (last full-year) results; for companies whose earnings swing fast (memory chips and other cyclicals/high-growth), a forward P/E on this year's expected earnings is more accurate.
- P/B
- Price relative to net assets (equity). Around 1x means it trades near book value; below 1x means below book.
- P/S
- Price relative to a year's revenue — useful for growth companies with thin earnings.
- Net debt / EV
- Net debt = interest-bearing debt − cash. Negative means more cash than debt (net cash). EV (enterprise value) = market cap + net debt, closer to what it would cost to buy the whole business.
- EV/EBIT · EV/EBITDA · EV/Sales
- Enterprise value against operating profit (EBIT), EBITDA, or revenue. Unlike P/E these reflect debt and cash; lower is cheaper relative to earnings power or sales.
- FCF / FCF yield
- Free cash flow = operating cash − capex, the cash actually left over. FCF yield = FCF ÷ market cap; higher means more cash generated per unit of market value.
- Intrinsic value (DCF)
- Future free cash flow (or, for some capex-heavy but profitable names, forecast earnings) discounted to today to estimate per-share value. Because it shifts a lot with the discount-rate and growth assumptions, it is shown as a bear/base/bull range, and the basis and assumptions are disclosed in one line beneath it.
- ROE
- How much profit the company earns in a year on its equity (%). Higher means better returns on capital.
- EPS / BPS
- Earnings per share / net assets (book value) per share.
- Operating / net margin
- Profit left from the core business / final profit after tax and interest, per unit of revenue.
- Debt ratio
- Debt relative to equity (%). Higher means more reliance on borrowing (norms vary by sector).
- Current ratio
- Assets convertible to cash within a year against debt due within a year. Above 100% leaves some short-term headroom.
- Interest coverage
- How many times operating profit covers the interest owed. Below 1x means operating profit alone struggles to cover interest.
- Dividend yield / payout ratio
- The year's dividend as a % of today's price / the share of earnings paid out as dividends.
- Revenue CAGR
- Multi-year growth expressed as a single yearly average (compound annual growth rate).
- RSI (short-term signal)
- Whether recent price action is overheated or beaten down. Above 70 is overbought, below 30 oversold.
- MA20 / MA60 (moving averages)
- The 20- and 60-day average price. Price above them signals a firmer short-term trend.
- vs 52-week high
- How far below the past year's peak the price sits now (%).
All figures are for reference only; how they read varies by sector and over time.
Sources: Korea FSC market-price API (data.go.kr), OpenDART, KRX/KIND — public data only.
Bong Stocks presents public-data-based information for reference only. It is not investment advice and contains no target prices, ratings, or buy/sell recommendations. Verify independently before making any decision.