Seoul Semiconductor makes and sells LEDs (light-emitting semiconductor devices) used in lighting, TVs, automobiles, and IT equipment, with patent-based high-efficiency products and automotive LEDs forming the backbone of revenue. In 2025 it posted an annual operating loss of ₩31.5 billion and a net loss of ₩51.4 billion, but in Q1 2026 it returned to profit with revenue of ₩238.2 billion, operating profit of ₩1.8 billion, and net profit of ₩8.8 billion. Worth noting recently: with the share of high-value products such as automotive lighting LEDs and Micro LEDs rising as earnings recover, the stock trades below its net assets (book value), giving it undervaluation appeal; on the other hand, the operating margin is still thin and part of the profit leans on one-off non-operating gains, so the durability of earnings needs further confirmation.
At-a-glance assessment financial health · growth · profitability · valuation
- The most recent full-year net result was a loss.
- Revenue fell 7.1% year over year (3-year trend: mixed).
- Most recent quarter (Q1 2026) revenue was 0.4% lower than a year earlier.
- ROE is -8.3% (controlling-interest basis). It is below the sector average.
- Operating margin is -3.1%.
- P/E is hard to compute here, so this is read on P/B.
Ownership & governance As of 2025-12-31
Largest shareholder Lee Jung-hoon 13.59% (individual)
Controlling bloc incl. related parties 28.53%
With the controlling bloc holding 29%, control is maintained but the free float is relatively large.
🔎 In-depth analysis
- Seoul Semiconductor designs, produces, and sells LEDs (light-emitting semiconductor devices).
- Rather than the memory or system chips people usually think of, its core business is optical semiconductors that handle light.
- Its main products are backlights for TVs and monitors, indoor and outdoor lighting, and — an increasingly large share recently — LEDs for automotive headlamps and interior lights.
- Its business strategy is to differentiate not through low-price competition but through high-efficiency, high-reliability products, leaning on proprietary patented technology (structures that produce bright light from a small chip, for example).
- Revenue is sensitive to demand in downstream TV and lighting industries, but the direction is to lift profitability by growing higher-priced areas such as automotive and Micro LED.
- The current price is ₩9,490, below the 20-day line (₩11,413) and the 60-day line (₩13,125).
- The short-term flow is depressed.
- The one-month return is -27.8%, a sizable pullback.
- On a six-month basis, however, it is +48.8%, so it can be viewed as a retracement after a medium-term rebound.
- RSI (a gauge of short-term overbought or oversold conditions on a 0-100 scale) is 35.4, close to oversold.
- It sits about 48% below its 52-week high.
- On a 2025 basis, profitability metrics were in the red.
- ROE (how much is earned in a year per unit of equity) was -8.3% and the operating margin was -3.1%.
- But it matters that these are past results.
- In Q1 2026 both operating profit and net profit turned positive.
- The valuation is notably low.
- The P/B (how many times net assets the price represents) is 0.89, below 1x.
- That means the share price (₩9,490) is below net assets per share (₩10,630).
- The P/S (how many times revenue the price represents) is 0.55.
- Debt-adjusted metrics are not burdensome either.
- EV/Sales (enterprise value divided by revenue) is 0.66, and net debt (total borrowings minus cash) is about ₩80.6 billion.
- FCF yield (cash actually generated relative to market cap) is 6.79%, a sign that cash was earned even during the loss-making phase.
- That said, the debt ratio (debt to equity) is 178%, not low, so whether the earnings recovery continues is the key to financial stability.
- Revenue has passed through a stagnant, declining phase.
- 2025 revenue was ₩1,013.5 billion, down 7.1% from the prior year.
- Compared with five years ago (₩1,301.0 billion in 2021), it is a gentle downtrend.
- Earnings are more dramatic.
- In 2021 there was a net profit of ₩49.7 billion, but 2022 through 2025 were consecutive losses.
- The inflection is Q1 2026.
- Revenue of ₩238.2 billion was similar to a year earlier, but operating profit of ₩1.8 billion and net profit of ₩8.8 billion marked a return to profit.
- Compared with the ₩25.8 billion net loss in the same quarter a year earlier, it is a big reversal.
- The company officially guided Q2 2026 revenue to ₩270-290 billion (midpoint ₩280 billion), a figure about 17% above Q1.
- As high-value products such as automotive lighting LEDs and Micro LEDs grow, the structure allows earnings to improve in steps even without a large jump in revenue.
- For this reason, while earnings metrics cannot be viewed on last year's loss-making basis, on this year's expected earnings the price is not a heavy burden relative to profit.
- Earnings-related disclosures are at the center of the flow.
- Preliminary-results disclosures in April and May 2026 confirmed the Q1 return to profit.
- Operating profit, pre-tax profit, and net profit all turned positive.
- In May, through a fair disclosure (forward earnings outlook), the company itself guided Q2 revenue (₩270-290 billion).
- This is a signal that the company itself expects next-quarter revenue to rise.
- In March there were disclosures of the annual shareholders' meeting and a loan decision.
- In June, disclosures related to convening an extraordinary shareholders' meeting followed.
- There was also a May disclosure of an investor briefing (IR), showing the company continuing to communicate during an earnings-improvement phase.
- The crux is to view it not as a loss-making company but as a company that has just turned profitable.
- The share price is below net assets per share, and it is also low relative to revenue and enterprise value.
- Compared with LED optical-semiconductor peers that generally trade above 3x P/B, the discount is clear.
- The strong condition is evident.
- If TV and lighting demand recovers and automotive lighting LEDs and Micro LEDs grow, an improving high-value product mix can lift the margin in steps.
- The company's own guidance for a Q2 revenue increase also supports this direction.
- The cautionary condition is just as clear.
- Q1 operating profit of ₩1.8 billion is still thin, and the net profit includes a contribution from non-operating gains, so the quality of earnings needs more confirmation.
- If downstream TV and lighting demand weakens again or automotive growth slows, the profit could thin out.
- The debt ratio is also not low, so the durability of the earnings recovery is the key yardstick for this stock.
🔎 Valuation vs peers Undervalued
Domestic listed peers in the LED and optical-semiconductor and the semiconductor-device and packaging groups.
| Peer | P/E | P/B | ROE |
|---|---|---|---|
| Seoul Viosys | — | 3.80x | -19.80% |
| Nepes | 28.72x | 3.85x | 13.40% |
On last year's basis it was loss-making, so the P/E cannot even be calculated, making it hard to argue expensive or cheap on past earnings. Instead, on an asset and revenue basis the position is clear. At a P/B of 0.89 the price is below net assets, and at a P/S of 0.55 and EV/Sales of 0.66 it is low relative to revenue and enterprise value. Compared with LED and semiconductor peers such as Seoul Viosys (P/B 3.8) and Nepes (P/B 3.85), the discount to assets is large. Adding the Q1 2026 return to profit and the company's own guidance for a Q2 revenue increase, the price is also not a heavy burden relative to this year's expected earnings. Taken together, there are several grounds to view it as undervalued. However, the margin is still thin and the quality of the profit needs more confirmation — points to weigh alongside.
Earnings outlook company-stated · verified
| Type | Period | Revenue | Operating profit | Net profit |
|---|---|---|---|---|
| Next quarter | Q2 2026 | 2,700~₩290.0 billion | — | — |
Price history Close · MA20 · MA60
The latest close is ₩9,490 and the market capitalization is ₩553.3 billion. The price sits below its 20-day moving average (₩11,412) and below its 60-day moving average (₩13,125). It is under both its short- and medium-term moving averages, so the trend looks subdued. The RSI (a supplementary indicator that gauges the strength of gains versus losses over the past 14 days on a 0-100 scale) is 35.4, a neutral level. The one-month change is -27.8%, the three-month change is -7.9%, and the position relative to the 52-week high is -48.1%. Relative strength versus the KOSDAQ is 88 (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 89% of all stocks. Over the past three months it outpaced the index by 18.2%. 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 +18.20% / 6M +79.09% / 12M +35.07%
Key metrics vs sector median
Valuation
A net loss makes the P/E an unreliable valuation gauge. The P/B of 0.89x is below the sector median (2.10x).
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.
Intrinsic value (DCF estimate)
DCF (discounted cash flow) estimate — discount rate 11.0%, initial growth 4.0%→terminal 2.0%, 10-yr forecast, free-cash-flow basis. A reference range that shifts materially with assumptions.
Profitability & financials
The operating margin is -3.1%. The debt ratio is 178.0%, so the financial structure is moderate.
Growth FY2025 · annual report (consolidated)
| Item | 2023 | 2024 | 2025 | YoY |
|---|---|---|---|---|
| Revenue | $684.2M | $722.7M | $671.7M | -7.06% ↓ slower |
| Operating profit | -$32.7M | -$7.2M | -$20.9M | — |
| Net profit | -$14.8M | -$9.6M | -$34.1M | — |
| 5-year | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|
| Revenue | $862.3M | $735.3M | $684.2M | $722.7M | $671.7M |
| Operating profit | $41.9M | -$22.2M | -$32.7M | -$7.2M | -$20.9M |
| Net profit | $32.9M | -$728,910 | -$14.8M | -$9.6M | -$34.1M |
| Revenue CAGR | 4-yr avg -6.05% | ||||
Revenue fell 7.1% year over year (2023 ₩1.0 trillion → 2024 ₩1.1 trillion → 2025 ₩1.0 trillion), and the three-year trend is 'mixed'. The rate of decline widened from the prior year. Operating results are in the red, so a swing back to profit matters more than the growth rate here. Over the 5 years on record, revenue compound annual growth (CAGR) is -6.0%. The two-year revenue CAGR is -0.9%. In the most recent quarter (Q1 2026), revenue was 0.4% lower than the same period a year earlier.
Latest quarterly results Q1 2026 · vs year-ago
Technical indicators
What stands out
- P/E and P/B are both low versus peers, so the price looks inexpensive relative to earnings and assets.
Points to watch
- The most recent full year was a loss, so it is worth checking whether profitability recovers.
- Revenue fell 7.1% year over year (3-year trend: mixed).
Recent news & events searched · sourced
- 2026-05-12EarningsQ1 2026 consolidated preliminary results: revenue ₩238.2 billion, operating profit ₩1.8 billion, net profit ₩8.8 billion. Both operating and net profit swung from a year-earlier loss to a profit.An inflection signaling the end of the loss-making phase. Grounds for a re-valuation as a company that has just turned profitable. A factor improving short-term sentiment. Source
- 2026-05-12FilingFair disclosure (forward earnings outlook) guiding Q2 2026 revenue to ₩270-290 billion, about 17% above Q1.Confirms that the company's official revenue outlook points higher. A medium-term positive that supports expectations of a continued earnings recovery. Source
- 2026-05-08IRDisclosure of an investor briefing (IR) to announce Q1 results. Investor communication during an earnings-improvement phase.A channel to check the background of the earnings turn and the second-half strategy directly. A positive from the standpoint of improved information access. Source
- 2026-03-26FilingDisclosure of the annual shareholders' meeting results and a loan decision. Routine matters related to governance and cash management.Direct earnings impact is limited. Reference information for checking cash management and affiliate relationships. Source
Figure cross-check computed ↔ external
| Metric | Computed | External | Status | Source |
|---|---|---|---|---|
| Q1 2026 return to net profit | net profit ₩8.8 billion(base quarter net_income ₩8,753,582,936) | net profit 8,754 | Confirmed | link |
| Q1 2026 revenue | ₩238.2 billion(base quarter revenue ₩238,169,411,932) | revenue 238,169 | Confirmed | link |
| Q2 2026 revenue outlook | self-estimate revenue approx. ₩280.0 billion | 2,700~₩290.0 billion | Confirmed | link |
| 2026 annual net profit (internal estimate) | approx. ₩38.0 billion | — | Unverified | link |
Recent filings
- 2026-06-02Disclosure
- 2026-06-02Shareholders' meeting notice
- 2026-05-15PeriodicQuarterly report
- 2026-05-12Shareholders' meeting notice
- 2026-05-12Disclosure
- 2026-05-12Fair-disclosure notice
- 2026-05-12EarningsFair-disclosure notice (amended)
- 2026-05-08Disclosure
- 2026-04-15EarningsFair-disclosure notice
- 2026-03-27Amended filing
- 2026-03-26Disclosure
- 2026-03-26Shareholders' meeting notice
📖 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.