Celltrion, Inc. (KRX:068270) closed at ₩188,100 on Friday, September 4. The shares rose 0.5%. The company's market capitalisation was ₩43.8 trillion at Friday's close. That's roughly $31bn at an approximate ₩1,400 per dollar. The shares are about 20% below their 52-week high of ₩236,861.
The income statement gives no reason for that. Second-quarter revenue was ₩1,393.7bn, up 45% from a year earlier. Operating income was ₩451.8bn, up 86%, for a margin of 32.4%. The first quarter was also a record for a first quarter. The company's newer products include Zymfentra, Yuflyma and Steqeyma. It said newer products now make up more than 60% of sales. Korean press reported that Steqeyma, its Stelara biosimilar, reached a 16% share of the US market in July.
The balance sheet is where the story gets more interesting. Trade receivables were ₩2,220.1bn at the end of June. A year earlier they were ₩1,299.4bn. That is a 71% increase against a 45% increase in revenue. Customers are taking longer to pay, or the customers have changed, or both. My view is that this is the price of selling direct in the United States, and that it's a price worth paying, but it is a real cost that the margin headline doesn't show.
The trend is steady rather than sudden. Receivables were ₩1,299.4bn in June 2025. They reached ₩1,439.0bn in September and ₩1,790.4bn in December. They then reached ₩1,909.6bn in March and ₩2,220.1bn in June 2026. Quarterly revenue over the same five quarters started at ₩961.5bn. It then reached ₩1,029.0bn and ₩1,330.2bn. Next came ₩1,145.0bn and ₩1,393.7bn.
Divide one by the other. The ratio of receivables to a quarter's sales has gone from about 1.35 a year ago to about 1.59 now. In days, that's roughly 123 days of sales outstanding a year ago against 145 today. Three weeks more of the company's money sits with its customers than did in mid-2025.
Inventories were ₩2,940.5bn at the end of June against ₩2,712.1bn a year earlier. By contrast, that's up 8% on 45% revenue growth. The company is working inventory down relative to sales. It's receivables that are absorbing cash.
Until 2023, Celltrion sold through Celltrion Healthcare. That affiliated distributor bought product and carried the receivables. The merger folded that company into the manufacturer. Since then Celltrion has been building its own sales operation in the US and Europe. It sells Zymfentra in particular under a direct model to US payers and pharmacy-benefit managers.
That model changes who owes the company money and on what terms. A distributor pays on a schedule set between two affiliates. A US pharmacy-benefit manager pays on commercial terms. These run longer and involve rebates settled after the fact. The gross-to-net gap in US biologics is wide. The timing of rebate settlement shows up as receivables and accruals on the seller's books.
So a company whose fastest-growing product line is a US direct-sale drug should expect receivables to grow faster than revenue for a while. That's what the numbers show. The question is whether the growth stabilises once the mix settles.
The reassuring evidence is in the cash flow statement. Operating cash flow was ₩413.3bn in the second quarter and ₩651.4bn in the first half. That compares with first-half net income of ₩721.2bn. Roughly 90% of profit arrived as cash, even with receivables rising ₩430bn over the six months. I noted last week that this line more than doubled year on year, and it's the part of the improvement hardest to argue with.
Cash and equivalents fell to ₩1,076.3bn at the end of June from ₩1,288.7bn in March. That wasn't operations. Financing activities took out ₩375.8bn in the quarter, which is the share buyback and cancellation programme I covered on August 28. The company then approved a further ₩100bn buyback on August 31. It runs from September 1 to November 30. The company plans full cancellation.
A company that is stretching receivables because customers won't pay does not usually spend ₩375bn a quarter retiring stock. Management is behaving as though the receivables are collectible on schedule. The numbers so far agree.
Trailing twelve-month net income is about ₩1.58tn, which puts the shares near 28 times. That is a premium to the broader Korean market and a discount to what US biotech with 45% revenue growth would fetch. Book equity of ₩18.05tn puts the shares at 2.4 times. But ₩14.19tn of that book is intangibles from the 2023 merger. So tangible book is much smaller.
The multiple assumes that the 32.4% margin holds and that the new-product growth continues. Both depend on the US, and the US is where the receivables are growing.
The first risk is that the rebate accruals behind the receivables turn out larger than expected. US net pricing for biosimilars falls as more competitors enter. Stelara has several biosimilar rivals besides Steqeyma. If the rebates settle higher than accrued, some of the receivables will never arrive as cash. The half-year report doesn't break out the accrual.
The second is that the receivables ratio keeps climbing. A move from 123 to 145 days is explicable by mix. A move to 170 would mean something else, either customers stretching or product moving into channels that pay slowly. That is the number to watch, not the headline growth.
The third is regulatory, and it cuts both ways. I wrote last week that the FDA has been dismantling the comparative efficacy study requirement for biosimilars, which cuts Celltrion's development costs. The same change cuts everyone's costs, which means more rivals faster. A 16% share of the US ustekinumab market in July is a strong start. The company also has to defend that share against competitors with lower launch costs than Celltrion faced.
The third-quarter report is due in mid-November. It will show whether receivables crossed ₩2.4tn. If they did while revenue grew at a similar pace, the ratio has stabilised. Then the direct model's working-capital cost is a one-time step. If receivables keep outrunning sales, the margin story needs a cash-flow footnote.
Before that, watch the monthly US market-share data on Steqeyma and Zymfentra that Korean press reports from IQVIA. Share gains are what justify the receivables. If share stalls while receivables keep rising, the two lines are telling different stories. The balance sheet is usually the one to believe.
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.