Hyosung Heavy Industries (298040) fell 6.03% on 31 August to ₩2,963,000. Three days earlier I looked at this company against HD Hyundai Electric and concluded it earns less per won of revenue while trading on a higher earnings multiple. The stock has since come down about 3.8%, which changes the arithmetic a little and the argument not at all.
What I want to do here is different, and I think more important. Everyone agrees the transformer shortage is real. The question nobody seems to ask is which part of the earnings growth it produced — price or volume — because those two things have very different half-lives.
First-half revenue was ₩3,045.2bn against ₩2,601.4bn a year earlier, up 17.1%.
First-half operating income was ₩416.6bn against ₩266.6bn, up 56.2%.
Three and a quarter times the growth rate. That gap is the whole story, and it means Hyosung Heavy is not primarily selling more transformers. It is selling roughly the same equipment at much better prices.
The June quarter makes it starker. Revenue of ₩1,687.0bn was up only 10.6% from ₩1,525.3bn. Operating income of ₩264.3bn was up 60.9% from ₩164.3bn. Volume growth in the double digits is respectable for a heavy manufacturer. It is not what a 48 times earnings multiple is priced on.
Here is the operating margin by year, and it's worth reading slowly because the range is the point.
FY2021: 3.88%. FY2022: 4.08%. FY2023: 5.99%. FY2024: 7.41%. FY2025: 12.52%.
Then by quarter through the current cycle: 9.51%, 10.77%, 13.53%, 14.95%, 11.22%, and 15.67% in the June quarter just reported.
A business that ran at 4% for two consecutive years is now running at 15.67%. That is a quadrupling, and it happened in about three years without the revenue line doing anything remotely comparable — FY2021 revenue was ₩3,094.7bn against ₩5,968.5bn in FY2025, less than a doubling.
I don't think the 4% years were the true earnings power of this business. Grid equipment was in a decade-long capital drought and everyone was pricing to keep factories busy. But I also don't think 15.67% is, and the reason is on the company's own cash flow statement.
Purchases of property, plant and equipment were ₩122.6bn in the June quarter, against ₩47.6bn in the same quarter of 2025. That's up 157%. For the full year FY2025 the figure was ₩162.9bn against ₩84.0bn in FY2024, roughly a doubling. Property, plant and equipment on the balance sheet reached ₩2,477.9bn at 30 June, up 11.2% year over year.
A shortage produces high prices. High prices produce capacity. Capacity ends the shortage. Hyosung is doing exactly what it should do commercially and exactly what compresses the margin the market is capitalising, and it is not doing it alone — every transformer maker on earth is expanding into the same demand.
The lag is long, which is the bull's best defence. Transformer capacity takes years to commission and the order books stretch out past 2030. The margin probably has room to run. But the direction of travel after that is not genuinely in doubt, and a 48 times multiple has to be paid for by the years before the correction, not the years after.
To be fair to the other side, one number does support the volume story rather than just the price story.
Inventories were ₩1,683.2bn at 30 June against ₩1,277.1bn a year earlier, up 31.8%. Trade receivables were ₩1,524.5bn against ₩1,189.7bn, up 28.1%. Together that's ₩3,207.8bn tied up in work moving through the factory — 37.5% of total assets — and both grew far faster than the 10.6% revenue increase.
In a project manufacturer, inventory running well ahead of revenue is usually work in progress on contracts not yet delivered. It's the closest thing to an order book you can read off a balance sheet. So volume is coming, it just hasn't arrived in the revenue line yet.
Cash flow supports this too. First-half operating cash flow was ₩453.7bn against ₩263.1bn of net income. The profits are converting.
At ₩2,963,000 the market value is ₩27,628.6bn against ₩574.9bn of trailing net income and ₩2,728.8bn of equity. That is 48.1 times earnings and 10.1 times book.
Work backwards. Suppose you want to own this at 20 times earnings, which is not a demanding number for a company with a genuine structural tailwind. You need ₩1,381.4bn of net income. Net income has recently run at about 64% of operating income after finance costs and tax, so that means roughly ₩2,155bn of operating profit. Hold the June quarter's 15.67% margin — the best in the company's history — and you need ₩13.75tn of revenue.
Trailing revenue is ₩6,412.3bn. The requirement is 2.14 times that.
Doubling revenue is not impossible over five or six years for a company in this position. It is, however, exactly what today's price already contains, which means the transformer boom is not an argument for buying the stock. It's an argument for the stock not falling.
None of this touches the construction business, which on 1 August cost shareholders ₩346.3bn in assumed project finance debt after a missed completion obligation — 13.91% of consolidated equity, and something I wrote about separately. That obligation is not in the 30 June balance sheet I've been quoting.
It matters here because it changes the denominator in every multiple above. Book value of ₩2,728.8bn becomes something closer to ₩2,382bn on a look-through basis, and the price-to-book goes from 10.1 to about 11.6. Current liabilities of ₩4,919.0bn already exceeded current assets of ₩4,644.1bn before the assumption.
So the valuation I've described is the flattering version.
If AI data-centre connection demand and grid replacement in the United States and Europe are a fifteen-year build rather than a five-year catch-up, then the margin doesn't revert on any timeframe that matters to a holder today, and the capacity being added gets absorbed as fast as it's commissioned. The Memphis plant sells into the market where that demand is largest, and the AusNet framework signed in July points at a second geography doing the same thing for different reasons.
In that world 15.67% isn't a peak, it's a new floor, and 48 times earnings on a business compounding volume at double digits is defensible.
The gap between revenue growth and operating income growth. Right now it's 17.1% against 56.2%. If the third quarter shows revenue accelerating toward the profit growth rate, the order book is converting and the volume story is real. If profit growth slows toward the revenue rate instead, the margin has stopped expanding, and everything above the operating line was a price cycle that has just turned.
I'd also watch the capex line. Another quarter above ₩120bn tells you management thinks the demand is durable enough to build for. It also tells you when the supply arrives.
kstock reads DART every morning and writes up what moved — the contract, the buyback, the number that does not add up. The daily post and a Saturday roundup, by email.