At 1:29 p.m. KST on July 23, GnCenergy was up 29.5%, SK Gas 11.4%, LS ELECTRIC 11.2%, LS Materials 10.9% and Seojin System 12.6%. Korea’s AI data-center power theme had returned in force.
That price order is not the same as an investment ranking. GnCenergy has the cleanest backup-power exposure, but it had already risen 77.9% over the prior 20 sessions. LS ELECTRIC has a confirmed KRW 318.96 billion contract, yet trades near 61.6x 2026 earnings while foreign investors sold KRW 198.7 billion over 20 sessions. LG Electronics, by contrast, combines chillers, coolant distribution units and direct-to-chip cooling. Its shares fell 10.7% over the same window while foreign and real-money investors bought KRW 85.5 billion and KRW 105.3 billion.
That distinction drives this report: business directness and a good entry price must be scored separately.
Related context This is the market and flow update to the July 4 AI data-center power bottleneck map. Company-specific context is available in our work on GnCenergy, VinaTech and Bloom Energy, SK Gas LNG cold energy and SK Gas versus SK Oceanplant. See also the Exclusive Analysis Hub and Korean AI Companies Hub.
TL;DR
Korea’s data-center theme mixes operators, facility and power suppliers, and AI server component vendors. The first revenue capture often sits with power, cooling and backup-power suppliers. Operators initially carry capex and only generate attractive returns after securing utilization, power economics and tenant contracts.
We score 19 names across three dimensions.
| Dimension | Weight | What it measures |
|---|---|---|
| Fundamentals and direct exposure | 40% | Confirmed contracts, product and customer directness, repeat-order potential |
| Foreign and real-money flow | 35% | 20-session foreign flow plus insurance, funds, private funds and pensions |
| Valuation and entry position | 25% | Forward P/E, recent return, intraday spike and price response to flow |
The current risk-adjusted order is LG Electronics, Iljin Electric, Samsung SDS, GST and SK Gas.
| Bucket | Names | View |
|---|---|---|
| Begin watching or scaling | LG Electronics, GST | Lower price burden with accumulated flow |
| Flow-confirmation candidate | Iljin Electric | Direct orders and reasonable valuation, but foreign buying must persist |
| Wait for a pullback | Samsung SDS, SK Gas | Strong theses, less attractive after the July 23 move |
| High quality, early entry | SK Telecom, Sanil Electric, HD Hyundai Electric, Seojin System | Flow conflict, high expectations or balance-sheet questions |
| Do not chase | GnCenergy, LS ELECTRIC, Hyosung Heavy, VinaTech, LS Materials, Gaon Cable | Direct exposure is offset by price, valuation or weakening flow |
1. Method
| Item | Basis |
|---|---|
| Live price | Naver Finance at 13:29 KST on July 23, 2026 |
| 20-session return | June 24 close to July 22 close, adjusted Naver FChart prices |
| Investor flow | June 24 through July 22, Kiwoom REST ka10059, amount basis |
| Real money | Insurance, investment trusts, private funds and pensions; financial-investment desks excluded |
| Valuation | July 22 Naver/WiseReport consensus and July 23 intraday price |
We recalculated returns from Naver’s adjusted-price series because the local prices_daily table contained corporate-action adjustment errors in a few names. July 23 prices are intraday, not closing prices. Forward multiples for thin-consensus and loss-making companies are only rough reference points.
2. Three Different Data-Center Trades
Operators
Samsung SDS, NHN, SK Telecom, LG Uplus, KT and NAVER own or rent data-center and GPU capacity to sell cloud, GPUaaS and enterprise AI services. Their earnings path runs from site and power procurement to construction, anchor customers, utilization and finally operating profit.
SK Telecom’s up-to-15GW plan is a useful scale marker, but remains a plan that depends on sites, power, tenants and financing.1 NHN Cloud is one step further along, having begun service on a 7,656-B200-GPU cluster in Yangpyeong.2
Facility and power suppliers
Switchgear, transformers, cables, backup generators, ESS and cooling systems can recognize sales from the order and construction phase, before the operator reaches mature utilization. This is the most direct early-cycle listed-equity layer. The risks are one-off contracts, customer concentration, input costs and working capital.
AI server components
Samsung Electronics and SK Hynix memory, FADU enterprise SSD controllers, Isu Petasys networking PCBs and Samsung Electro-Mechanics or Daeduck substrates respond more to server configuration, accelerator units and memory content than to the number of buildings.
The key is timing. Facility suppliers capture the front end of the investment cycle. Operators capture recurring revenue and platform value later.
3. Direct Beneficiaries
| Area | Company | Ticker | Directness | Evidence |
|---|---|---|---|---|
| Distribution systems | LS ELECTRIC | 010120 | A+ | KRW 318.96bn of Bloom-linked North American data-center switchgear and distribution transformers |
| Backup generation | GnCenergy | 119850 | A+ | Naver, KT and LG Uplus references; Paju AIDC cooperation |
| Special transformers | Sanil Electric | 062040 | A | KRW 50.3bn Bloom-related U.S. data-center transformer contract |
| Power buffer | VinaTech | 126340 | A | KRW 41.2bn Bloom-related supercapacitor system contract |
| High-voltage cable | Iljin Electric | 103590 | A- | Repeat 275kV cable orders for Malaysian data centers |
| MV cable and bus duct | Gaon Cable | 000500 | A- | U.S. AI data-center medium-voltage cable and local capacity expansion |
| Grid package | HD Hyundai Electric | 267260 | A- | North American data-center and grid transformers and distribution packages |
| Transmission | Hyosung Heavy Industries | 298040 | B+ | High-voltage transformers and reactors for grid expansion |
| Cooling | LG Electronics | 066570 | A- | Chillers, CDUs and direct liquid cooling as an integrated package |
LS ELECTRIC’s contract equals 6.42% of 2025 revenue and runs from April 28, 2026 to March 29, 2027.3 It is among the clearest disclosed contracts in the theme.
LG Electronics is different. Cooling is not yet large enough to drive group earnings, but it is one of the few large listed Korean vendors able to offer chillers, a 1.4MW CDU, direct-to-chip cooling and air systems together.4 In the LG group’s Paju AIDC design, LG Electronics provides cooling, LG Energy Solution provides power equipment and LG Uplus operates the site.5 The company said chiller orders tripled in 2025 and expected full-scale order and revenue recognition from 2026.6
4. ESS, Power Quality and Fuel
The second line includes Seojin System’s enclosures and racks, Samsung SDI and LG Energy Solution battery systems, LS Materials ultracapacitors, Samwha Capacitor power components and SK Eternix’s distributed-power and PPA optionality.
VinaTech’s move from cells to system-level delivery can raise content value, but customer concentration and production margins remain decisive. Seojin System shows a sharp flow conflict: foreigners bought KRW 128.9 billion over 20 sessions, while real-money investors sold KRW 30.5 billion and the stock fell 34.7%. Its roughly 11.5x 2027 P/E should be treated as a turnaround estimate, not as proven cheapness.
SK Gas offers an unusually broad option set across the 1.2GW Ulsan GPS plant, KET LNG terminal, LNG cold energy and SK’s AIDC buildout. The missing bridge is economic ownership: the power contract, cold-energy tariff, PPA economics and profit attributable to SK Gas are not public.
5. Operators
| Company | Ticker | Core asset | What must be proven |
|---|---|---|---|
| Samsung SDS | 018260 | Samsung Cloud and 60MW Gumi AI data center | Customer ramp and cloud-margin conversion |
| NHN | 181710 | Gwangju/Yangpyeong AI data centers and GPUaaS | Utilization, pricing and post-depreciation returns |
| SK Telecom | 017670 | Ulsan and DSX large-scale AI Cloud | Financing, tenants, utilization and ROIC |
| LG Uplus | 032640 | Pyeongchon and Paju AIDC | Occupancy and long-term leases |
| KT | 030200 | kt cloud and IDC | Indirect listed exposure because kt cloud is private |
| NAVER | 035420 | GAK Chuncheon/Sejong and own AI Cloud | AI-service monetization, not only infrastructure |
Samsung SDS has a 60MW Gumi AI data-center plan and said an anchor customer had already been secured.7 Its balance sheet and captive demand make it the most comfortable operator exposure, but a 22x-plus 2026 P/E needs cloud and generative-AI revenue to lift margins.
SK Telecom has excellent recent flow: foreign investors bought KRW 71.5 billion and real money KRW 80.1 billion. At around 17x 2026 earnings, however, the market is already assigning some AI-infrastructure value. The next rerating needs contracted customers and an explicit return framework, not only a 15GW ambition.
6. The Current Top Ten
This is an entry ranking, not a permanent business-quality ranking.
| Rank | Company | 20D return | Foreign / real money | Current valuation | July 23 intraday | View |
|---|---|---|---|---|---|---|
| 1 | LG Electronics | -10.7% | +KRW 85.5bn / +105.3bn | 2026E P/E 15.0x | KRW 184,300, +0.9% | Accumulation candidate |
| 2 | Iljin Electric | -17.8% | -24.3bn / +10.7bn | 2026E P/E 19.3x | KRW 64,600, +6.1% | Flow-turn candidate |
| 3 | Samsung SDS | +3.3% | +0.9bn / +57.4bn | 2026E P/E 22.4x | KRW 207,000, +5.6% | Quality core |
| 4 | GST | -16.0% | +7.7bn / +4.7bn | TTM P/E about 14.4x | KRW 43,050, +1.7% | Deep-alpha candidate |
| 5 | SK Gas | +10.1% | -0.4bn / +7.4bn | 2026E P/E 4.6x | KRW 254,000, +11.4% | Wait for pullback |
| 6 | SK Telecom | +3.4% | +71.5bn / +80.1bn | 2026E P/E about 17.0x | KRW 99,000, +5.2% | Great flow; verify ROIC |
| 7 | LG Uplus | +4.6% | -2.2bn / +31.7bn | 2026E P/E 8.7x | KRW 14,730, +0.6% | Defensive AIDC |
| 8 | Sanil Electric | -25.2% | +28.9bn / -33.3bn | 2026E P/E 26.1x | KRW 177,200, +6.3% | Wait for institution turn |
| 9 | HD Hyundai Electric | -15.2% | -148.1bn / +14.5bn | 2026E P/E 31.8x | KRW 857,000, +7.8% | Great company, early entry |
| 10 | Seojin System | -34.7% | +128.9bn / -30.5bn | 2027E P/E about 11.5x | KRW 40,800, +12.6% | High-risk turnaround |
7. Why LG Electronics Ranks First
LG Electronics has the best balance of product breadth, flow, valuation and unpriced optionality.
It can combine chillers, CDUs, direct liquid cooling and air systems. Foreign and real-money investors bought together while the share price fell 10.7% over 20 sessions. At roughly 15x 2026 earnings, it is cheaper than the large electrical-equipment leaders. The July 23 move was also limited to about 1%, reducing chase risk.
The cooling business still needs proof at group level. If global orders translate into disclosed revenue and margin, the multiple can expand. If cooling orders lag while core-business profitability weakens, the option should not be assigned a large value.
8. Iljin Electric, Samsung SDS, GST and SK Gas
Iljin Electric
Iljin combines direct data-center cable orders with a lower multiple than the large electrical-equipment leaders. Real money bought KRW 10.7 billion over 20 sessions, and foreign flow turned positive by about KRW 5.8 billion over the latest five. A further three to five sessions of foreign buying would turn the case from oversold to flow reversal.
Samsung SDS
Real money bought KRW 57.4 billion over 20 sessions and was a net buyer on 16 of those days. The share price rose only 3.3%. The 60MW Gumi project, Samsung Cloud and enterprise generative AI make it the safest operator exposure, but an entry near KRW 200,000 would be more attractive after the July 23 rise.
GST
GST is not yet a proven data-center cooling supplier. The case is a profitable semiconductor scrubber business with low leverage plus a low-cost immersion-cooling option. Foreign and real-money flow were both positive while the stock fell 16%. A commercial cooling order, not another pilot, is the catalyst.
SK Gas
SK Gas is the cheapest name in the group at about 4.6x 2026 earnings, but the July 23 11.4% rise reduced short-term margin of safety. A revisit to KRW 230,000-240,000 or a disclosed power/cold-energy contract would offer a cleaner entry.
9. High-Quality Names to Wait On
SK Telecom has the best flow but needs financing, tenant and ROIC evidence. LG Uplus is a lower-multiple defensive AIDC exposure, though the profit contribution remains small. Sanil Electric has a strong Bloom contract and high margins, but real money sold KRW 33.3 billion. HD Hyundai Electric’s order quality is excellent, but 31.8x 2026 earnings and heavy foreign selling leave limited room for error. Seojin System needs institutional flow, working-capital and cash-flow confirmation.
10. Do Not Chase Direct Exposure
GnCenergy is the cleanest backup-power beneficiary, but a 77.9% 20-session gain and a 29.5% intraday rise leave poor entry asymmetry. LS ELECTRIC’s contract is real, but so are a 61.6x 2026 P/E, KRW 198.7 billion of foreign selling and an 11.2% intraday rise. Hyosung Heavy combines strong earnings with a roughly 34x multiple and selling by both foreign and real-money accounts. VinaTech has a real Bloom contract but a trailing loss and real-money selling. LS Materials and Gaon Cable lack a comfortable combination of confirmed incremental earnings, valuation and flow.
11. Action Framework
| Name | Approach | Confirmation |
|---|---|---|
| LG Electronics | Scale gradually | Support in the mid-KRW 180,000s, continued dual flow, cooling revenue conversion |
| GST | Small pilot position | KRW 41,000-43,000 support, stable core earnings, commercial cooling order |
| Iljin Electric | Flow-confirmation entry | Three to five more sessions of foreign buying and acceptance near KRW 64,000 |
| Samsung SDS | Wait for pullback | Re-test near KRW 200,000 with continued real-money buying |
| SK Gas | Wait for price or contract | KRW 230,000-240,000 or disclosed AIDC power/cold-energy economics |
The upside catalysts are additional LG Electronics cooling orders, repeat Iljin data-center cable contracts, Gumi utilization and cloud-margin evidence at Samsung SDS, a commercial immersion-cooling order at GST, and disclosed PPA or cold-energy economics at SK Gas.
The thesis fails if data-center starts and equipment orders are delayed, large contracts prove one-off, input and financing costs erase backlog margins, operators cannot achieve utilization, or cooling and ESS products remain pilots rather than commercial revenue.
Conclusion
The Korean AI data-center theme needs three separate lenses: operators, power and cooling suppliers, and server components. Suppliers capture the front of the investment cycle through orders and backlog. Operators earn the long-duration value only after filling their centers and recovering power and depreciation.
LS ELECTRIC and GnCenergy lead on directness. Once price and flow are included, the ranking changes.
The current order is LG Electronics, Iljin Electric, Samsung SDS, GST and SK Gas.
The next returns are likely to depend less on whether a company can tell an AI data-center story and more on three questions: Is there a contract? Is durable capital buying? How much is already in the price?
Sources
Price and flow data come from the Korea Invest Insights local database, Naver FChart and Kiwoom REST ka10059. This report is for research and information only and is not investment advice.