DI: Shares More Than Double in a Year as Revenue Doubles and Margins Widen, While Model Estimate Sits Below Price

Thesis

The data supports a clear step-up in the business. Revenue grew 102.0% in 2025 to ₩432.3B, and trailing twelve-month revenue to H1 2026 is ₩477.3B. Operating income rose from ₩3.1B in 2024 to ₩72.8B on a trailing basis, and ROE reached 16.0%.

The share price has moved faster still: +41.6% in one month, +103.8% in three months and +112.1% in one year, and it sits near the 52-week high of ₩45,850 (low ₩15,550). Trailing P/E is 41.1 and P/B is 5.7, versus year-end 2025 figures of 118.6 and 3.7. Net margin (6.1%) is much lower than operating margin (15.3%), and free cash flow is only ₩3.5B, so cash conversion is not yet as strong as the earnings growth. Investor flow, foreign ownership and short-balance data are not available, so we cannot say who is driving the move. No news headlines are in the data.

Business overview

DI is a KOSPI-listed company in the medical and precision devices sector, founded on 1961-03-16 and listed on 1996-07-31. It has 28.3 million listed shares and a market capitalization of about ₩1.2T. Co-CEOs are listed as 박원호 and 조윤형. Revenue was stable at ₩226.6B in 2021, ₩231.0B in 2022, ₩214.5B in 2023 and ₩214.0B in 2024, before doubling in 2025. Filings show frequent major sales or supply contract disclosures in 2026 (June 10 twice, June 17, July 2, an amendment on July 30, and October 1), though contract sizes and counterparties are not in the data.

Financial analysis

All figures come from filed financial statements (DART). Revenue: ₩226.6B (2021), ₩231.0B (2022), ₩214.5B (2023), ₩214.0B (2024), ₩432.3B (2025), and ₩477.3B trailing to H1 2026. Operating income: ₩16.5B, ₩11.2B, ₩6.1B, ₩3.1B, ₩36.5B, and ₩72.8B trailing. Operating margin went from 1.4% in 2024 to 8.4% in 2025 and 15.3% trailing.

Net income was ₩5.1B in 2025 and is ₩29.2B trailing (net margin 6.1%). ROE moved from 0.7% in 2024 to 3.2% in 2025 and 16.0% trailing. Liabilities to equity is 93.9%. Cash is ₩58.3B; borrowings are not available. Trailing free cash flow is ₩3.5B, small relative to operating income.

Valuation

At ₩42,400, trailing P/E is 41.1, P/B 5.7, P/S 2.5, and dividend yield 0.7%. EV/EBITDA is not available; enterprise value is about ₩1.14T. Year-end 2025 P/E was 118.6 and P/B 3.7, so P/E has fallen as earnings rose while P/B has risen.

Peers: TSE P/E 32.6, P/B 7.2; Kctech 27.1 and 4.1; Park Systems 90.5 and 6.2; Classys 14.1 and 3.5; Curiox Biosystems not available. DI's P/E sits in the middle of this range and its P/B is in the upper half.

The DCF model (5-year discounted cash flow, 7.9% rate, TTM to H1 2026) gives a model estimate based on the assumptions shown of ₩24,446 per share in the base case, ₩13,796 bear and ₩41,979 bull. The current price is above the base case and slightly above the bull case. This is a model output, not a target or a reason to buy or sell.

Catalysts

• An investor relations (IR) event is scheduled for 2026-10-13, which may add detail on the business.
• A major sales or supply contract was filed on 2026-10-01, continuing a run of contract disclosures since June.
• The half-year report (filed 2026-08-14) and preliminary earnings (2026-08-03) established the current trailing figures.
• A 5%+ holding report was filed on 2026-09-07, indicating a change in significant shareholdings, though details are not in the data.
• Further contract filings or amendments, like the 2026-07-30 amendment, could change how revenue is perceived.

Risks

• The price is above the DCF base case of ₩24,446 and near the bull case, so the market is pricing in more than the base assumptions.
• Shares rose 103.8% in three months and trade near the 52-week high, which leaves room for sharp moves in either direction.
• Free cash flow of ₩3.5B is small against ₩72.8B of operating income, so earnings are not yet fully converting to cash.
• Revenue was flat to declining from 2021 to 2024, so the recent surge is a short track record.
• Investor flows, foreign ownership, short interest and borrowings are not available, limiting visibility on positioning and leverage.

Closing view

The filings show a real change in scale and profitability: revenue doubled, operating margin widened to 15.3% and ROE reached 16.0%. Against that, the share price has more than doubled in a year, trailing P/E is 41.1, cash generation is thin, and the model estimate based on the assumptions shown is below the market price. Missing data on flows, short interest and debt means the picture is incomplete. The evidence supports a strong operating recovery, while leaving open how much of it the current price already reflects.

Model estimate of fair value

Bear

₩13,796

-64%

Base

₩24,446

-35%

Bull

₩41,979

+11%

Model estimate based on the assumptions shown. Not a price target and not a buy or sell signal.

Base case of the 5-year discounted cash flow model on the stock's Valuation tab (statements TTM to H1 2026; discount rate 7.9%). Bear and Bull move the main assumptions by fixed steps. See and change the assumptions

Filings and data used

• Investor relations (IR) eventOct 13, 2026
• Major sales or supply contractOct 1, 2026
• 5%+ holding reportSep 7, 2026
• Investor relations (IR) eventAug 20, 2026
• Half-year report (Jun 2026)Aug 14, 2026
• Other management mattersAug 7, 2026
• Preliminary earnings (consolidated)Aug 3, 2026
• Amended: Major sales or supply contractJul 30, 2026
• Major sales or supply contractJul 2, 2026
• Major sales or supply contractJun 17, 2026
• Major sales or supply contractJun 10, 2026
• Major sales or supply contractJun 10, 2026
• Daily prices up to 2026-10-12
• Financial statements, trailing 12 months as of H1 2026
• Our fair value model, statements as of TTM to H1 2026

Report history

1. Oct 13, 2026InitiationStart of coverage (300 largest)DI: Shares More Than Double in a Year as Revenue Doubles and Margins Widen, While Model Estimate Sits Below Price