ISC makes 'test sockets,' the parts that connect chips to test equipment during the step where semiconductors are checked for proper operation after fabrication. It was the first in the world to mass-produce 'rubber sockets,' made by embedding fine conductive particles in silicone, and holds the world's largest market share, in a structure where demand tracks test volume like a consumable, rising as more chips are tested. On April 27, 2026 first-quarter provisional results confirmed a surge in revenue and profit, within which AI-chip-related revenue made up about 81% of the total, showing the center of gravity shifting quickly to AI, and the company paired this with an early-April treasury-stock disposal report and a 2025 dividend of ₩850 per share (payout ratio 31%). What stands out lately is that its world-leading position makes it a direct beneficiary of rising AI-chip test volume and its near-net-cash balance sheet lets it fund expansion on its own, so last year's P/E of 64x falls to around 40x on this year's earnings, similar to or below the top of the peer group; still, results are tied to the AI/HBM investment cycle and a handful of large customers, so if test demand turns down, its consumable nature can amplify volatility.
At-a-glance assessment financial health · growth · profitability · valuation
- Debt ratio, current ratio and interest burden all look healthy.
- Revenue rose 26.2% year over year, and the pace is quickening (3-year trend: rising).
- Most recent quarter (Q1 2026) revenue was 115.5% higher than a year earlier.
- ROE is 10.5% (controlling-interest basis). It is above the sector average.
- Operating margin is 27.3%.
- The forward P/E sits above the sector median, reflecting elevated expectations.
Ownership & governance As of 2025-12-31
Largest shareholder SKC 45.03% (corporate)
Controlling bloc incl. related parties 48.9%
With the controlling bloc holding 49%, the ownership structure is stable.
🔎 In-depth analysis
- ISC makes the 'test sockets' that connect chips to test equipment during the step where semiconductors are checked for proper operation after fabrication.
- In particular it was the first in the world to mass-produce 'rubber (silicone rubber) sockets,' made by embedding fine conductive particles in silicone, and holds the world's largest market share in this field.
- Because each chip is seated in a socket and screened for defects via electrical signals, socket demand tracks test volume like a consumable, rising as more chips are tested.
- Revenue splits between sockets for AI chips such as GPUs and ASICs and sockets for memory (including HBM) and system chips, and in the first quarter of 2026 AI-chip-related revenue reached about 81% of the total, showing the business's center of gravity shifting quickly toward AI.
- Major customers are domestic and overseas chipmakers including Samsung Electronics, SK Hynix, and Micron, and the company is part of the SK Group (SKC is the largest shareholder).
- The latest close is ₩141,800 and the market cap is ₩3.0 trillion.
- The price sits below both its 20-day moving average (₩180,410) and its 60-day line (₩209,235).
- Trading below both the short- and medium-term moving averages, the trend is on the subdued side.
- The RSI (a gauge that scores upward versus downward momentum over the past 14 days on a 0-100 scale) is 33.8, a neutral reading.
- The stock is down 21.5% over one month and 40.7% over three months, and it stands 47.7% below its 52-week high.
- Its relative strength versus the KOSDAQ is 91 (on a 1-99 scale that converts one-year return against the index, weighting recent performance more heavily; higher means stronger than the market), placing it in roughly the top 8% by strength across all stocks.
- Over the past three months it has lagged the index by 24.3%.
- Chart signals are best read alongside trading volume and disclosure dates.
- On a 2025 basis the P/E is 53.55x and the P/B is 5.60x, which look high on the numbers alone.
- But this should be read as based on 'last year's earnings,' before profit began rising in earnest.
- Profitability is solid, with an operating margin of 27.3% and a net margin of 25.5%, both in the high-twenties range.
- ROE (how much is earned on equity in a year) is 10.5%, with room to improve as earnings rise.
- The balance sheet is very stable: a debt ratio (total debt relative to equity) of just 15.9% and a current ratio of 539% give ample short-term liquidity, in effect a near-net-cash structure.
- The long-run trend is upward but with clear cyclicality tied to the chip cycle.
- Revenue grew in the 20% range for two straight years, from ₩140.2 billion in 2023 to ₩174.5 billion in 2024 to ₩220.2 billion in 2025, and profit recovered in steps after passing the industry trough of 2023 (an operating loss in the third quarter).
- The first quarter of 2026 is especially an inflection point: quarterly revenue of ₩68.3 billion (+115% year over year), operating profit of ₩23.6 billion (+238%), and net profit of ₩20.6 billion (+201%), with the operating margin climbing to about 35%.
- Socket revenue for AI chips (GPUs and ASICs) rose about 191% year over year to drive growth, and as the higher-value system-level test (SLT) share passed 60%, the margin itself improved structurally.
- On top of this, the company completed the Vietnam Plant 1 expansion early for full operation from October and will add a Plant 2 within the year to grow capacity, so there is room for more volume to load as the year progresses.
- On this earnings trajectory, this year's net profit rises well above last year's ₩56.1 billion, in which case the forward P/E on the current market cap falls to around 40x.
- In other words, the 64x on last year's earnings is a pre-inflection number, and on this year's earnings the valuation burden eases considerably.
- Disclosures center on results and capital return.
- The April 27 first-quarter 2026 provisional results confirmed a surge in revenue and profit, and in early April a treasury-stock disposal report showed a shareholder-related step using treasury shares.
- The dividend was ₩850 per share for 2025 (a dividend yield of about 0.5%, payout ratio 31%), so it pays a dividend alongside growth.
- Over recent months it has held several IRs to communicate AI-socket growth and expansion plans to the market.
- The points to watch are clear.
- As the world's leading test-socket maker, ISC is a direct beneficiary of rising AI-chip test volume, and in the first quarter of 2026 revenue and profit surged together to prove it in results.
- The balance sheet is a stable near-net-cash structure, so it can fund expansion from its own resources.
- Last year's P/E of 64x looks heavy, but for an earnings-inflection name, on a forward (this-year) basis it comes down to around 40x, similar to or even below the top of the peer group; given the pace of growth, it is hard to call today's value expensive.
- The caution is that the business is tied to chip test volume and the AI investment cycle.
- It is strong while AI/HBM investment keeps expanding, but if customers' capex or test demand turns down, its consumable nature can amplify earnings volatility.
- Revenue is also concentrated in a handful of large customers and the AI segment, making it sensitive to demand shifts at specific customers or products.
- In sum, this is a name where 'earnings leverage works powerfully as long as the AI-chip investment cycle holds, and volatility rises when that cycle slows.'
🔎 Valuation vs peers Fairly valued
Compared against back-end semiconductor test-component makers (sockets and test parts): Leeno Industrial (a global leader in pogo-pin sockets) and TSE (test parts and equipment).
| Peer | P/E | P/B | ROE |
|---|---|---|---|
| Leeno Industrial | 35.11x | 7.30x | 20.78% |
| TSE | 64.81x | 6.33x | 9.77% |
| ISC | 53.55x | 5.60x | 10.46% |
On last year's (2025) earnings the P/E of 64x is lower than TSE (80x) among the three but higher than Leeno Industrial (41x), so on the surface a premium appears. But ISC is an earnings-inflection name whose first-quarter net profit rose nearly threefold year over year, so the P/E on last year's earnings overstates the true value. On a forward basis that reflects this year's earnings trajectory, the P/E comes down to around 40x, similar to or even below Leeno Industrial, while ISC's growth pace (revenue and profit growth) is faster. Its P/B, at 6.7x, is also the lowest of the three. Accordingly, given the phase in which earnings are scaling, this is a 'fairly valued' level, and on a forward basis it leans closer to undervalued. That said, because the valuation rests on the AI investment cycle continuing, the burden could grow if the cycle slows, so rather than declaring it undervalued we read it as fairly valued.
Price history Close · MA20 · MA60
The latest close is ₩141,800 and the market capitalization is ₩3.0 trillion. The price sits below its 20-day moving average (₩180,410) and below its 60-day moving average (₩209,235). 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 33.8, a neutral level. The one-month change is -21.5%, the three-month change is -40.7%, and the position relative to the 52-week high is -47.7%. 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 24.3%. 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 -24.27% / 6M +46.42% / 12M +131.13%
Key metrics vs whole-market median
Valuation
The P/E of 53.55x is above the whole-market median (13.81x). The P/B of 5.60x is above the whole-market median (1.15x). That said, this P/E is based on last year's (trailing) results. With recent quarterly earnings up sharply, the trailing P/E can look higher than it really is, so a precise read is best done on this year's expected (forward) earnings.
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
Return on equity (ROE) is 10.5%, above the whole-market average (5.0%). The operating margin is 27.3%. The debt ratio is 15.9%, so the financial structure is stable.
Growth FY2025 · annual report (consolidated)
| Item | 2023 | 2024 | 2025 | YoY |
|---|---|---|---|---|
| Revenue | $92.9M | $115.6M | $145.9M | +26.20% ↑ faster |
| Operating profit | $7.1M | $29.7M | $39.8M | +34.10% ↓ slower |
| Net profit | $8.8M | $36.2M | $37.2M | +2.68% ↓ slower |
| 5-year | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|
| Revenue | $95.9M | $118.6M | $92.9M | $115.6M | $145.9M |
| Operating profit | $24.9M | $37.0M | $7.1M | $29.7M | $39.8M |
| Net profit | $20.0M | $29.1M | $8.8M | $36.2M | $37.2M |
| Revenue CAGR | 4-yr avg 11.07% | ||||
Revenue rose 26.2% year over year (2023 ₩140.2 billion → 2024 ₩174.5 billion → 2025 ₩220.2 billion), and the three-year trend is 'rising'. The pace of growth also quickened from the prior year. Operating profit rose 34.1% year over year. The pace of that profit growth is gradually easing. Over the 5 years on record, revenue compound annual growth (CAGR) is 11.1%. The two-year revenue CAGR is 25.3%. In the most recent quarter (Q1 2026), revenue was 115.5% higher than the same period a year earlier.
Latest quarterly results Q1 2026 · vs year-ago
Technical indicators
What stands out
- ROE of 10.5% points to solid profitability.
- Revenue grew 26.2% year over year, a sign of growth.
- The balance sheet is stable in terms of debt and liquidity.
Points to watch
- The price is high versus peers, so expectations already appear priced in.
Recent news & events searched · sourced
- 2026-04-27EarningsFirst-quarter 2026 provisional results: revenue of ₩68.3 billion (+115% year over year), operating profit of ₩23.6 billion (+238%), net profit of ₩20.6 billion (+201%). The operating margin improved sharply to about 35%.An inflection point where expanding AI-chip socket demand was confirmed in results. The key event that reframes last year's valuation onto this year's earnings. Source
- 2026-04-06FilingTreasury-stock disposal report disclosed. A shareholder-related step using treasury shares was completed.Use of treasury shares ties into free float and shareholder value, signaling capacity for capital return backed by a net-cash balance sheet. Source
- 2026-05-15FilingFirst-quarter 2026 quarterly report filed. The revenue and profit gains announced in the provisional results were confirmed in formal financial statements.Provisional figures confirmed as formal numbers, raising confidence in the earnings inflection. Source
- 2026-06-05IRIR (investor briefing) held. Shared AI-chip socket growth and capacity-expansion plans such as the Vietnam buildout with the market.A communication event conveying the second-half volume-expansion and buildout roadmap, providing visibility on the durability of growth. Source
Figure cross-check computed ↔ external
| Metric | Computed | External | Status | Source |
|---|---|---|---|---|
| Market capitalization (current price x share count) | ₩3.0 trillion | ₩3.0 trillion | Confirmed | link |
| First-quarter 2026 revenue and operating profit | revenue 683, operating profit 236 | revenue ₩68,272,305,646, operating profit ₩23,616,393,149 | Confirmed | link |
| 2026 full-year profit (forward) | self-estimate net profit approx. ₩90.0 billion(forward PER approx. 40x) | — | Unverified | link |
Recent filings
- 2026-06-05Disclosure
- 2026-06-02OwnershipOwnership-change filing
- 2026-05-29Large-business-group status disclosure
- 2026-05-18Amended filing
- 2026-05-15PeriodicQuarterly report
- 2026-05-06Disclosure
- 2026-04-27EarningsFair-disclosure notice
- 2026-04-15OwnershipOwnership-change filing
- 2026-04-06TreasuryTreasury-stock disposal decision (amended)
- 2026-04-06TreasuryTreasury-stock disposal decision (amended)
- 2026-04-03Disclosure
- 2026-04-03Disclosure
📖 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.