KB Financial Group Inc. (KRX:105560) fell 3.32% on Friday, September 4. It closed at ₩172,000 on a day the KOSPI gained 1.64%. The day's buying went into semiconductors and holding companies. Banks were left behind. KB is the biggest of them and fell the most. The company's market capitalisation was ₩61 trillion at Friday's close. That's roughly $43.6bn at an approximate ₩1,400 per dollar. Reported equity at the end of June was ₩62.7tn.
That puts KB at about 0.97 times book on the simplest calculation, or just above one on the stricter common-equity basis I laid out on August 27. Either way, it is the only Korean bank holding company priced at what it owns. Korean press estimates put Shinhan in the high 0.8s, Hana around 0.75 and Woori lower still. Two years ago all four traded between 0.4 and 0.6 times book. The question was why the market hated Korean banks. Now the question is why it likes KB and only KB.
My answer is that the market is not paying for KB's earnings. It's paying for a rule. KB was the first Korean bank to tie its payout to a capital ratio rather than to a payout target. That rule is worth more than a promise because it removes the board's discretion. The rest of this piece is about how the rule works and what would break it.
In Korea's 2024 corporate value-up program (기업가치 제고 계획), listed companies filed voluntary plans for how they would raise returns to shareholders. Most banks promised a total shareholder return ratio, usually 50% of net income by some future year. KB did something different. It promised no ratio at all.
Instead, KB said any common equity tier 1 capital above 13% at year-end would fund first-half returns. Any capital above 13.5% at mid-year would fund second-half returns. CET1 is the core regulatory capital ratio a bank must hold against its risk-weighted assets. Above the threshold, the money is surplus. Below it, the money stays.
That framing does two things. It makes the payout automatic, so investors don't have to guess what the board will decide. And it makes the payout grow with capital rather than with profit. That matters at a bank whose net interest income has stopped growing. I noted on August 27 that KB's record first half came from fees rather than lending. Under a profit-linked payout, a flat net interest margin would cap the return. Under a capital-linked payout, it doesn't.
KB ended June with a CET1 ratio of 13.74%, the highest of the four large groups. The surplus over 13% for 2026 came to ₩2.82tn. The company has already assigned it. It allocated ₩1.62tn to the annual dividend. It assigned ₩1.2tn to buying back and cancelling shares in the first half. Management discussed a further ₩180bn of second-half capacity on the second-quarter call. It said it would use this flexibly. It was also studying a shift toward a return-on-equity-linked framework. Brokers now expect the 2026 total shareholder return ratio to land near 58%.
Shinhan, Hana and Woori have all raised their payouts since 2024. Shinhan's 2025 return ratio was 50.2%. Hana's was 46.8% and Woori's was 39.8%, against KB's 52.4%. Each of those rose by about ten percentage points in a year. The direction is the same across the sector.
What differs is the mechanism. Shinhan has set a 50% target with the phrase "plus alpha" attached. Korean press has framed the summer as a contest between KB's blunt formula and Shinhan's discretionary extra. Hana's plan still expresses returns as a ratio of profit. When a bank's ratio is a target, the board can miss it and explain. When it's a formula on the balance sheet, the number is visible each quarter before the board meets.
That is the difference the market is paying for. A holder of KB knows roughly what the next return will be. They know on the day the quarterly capital ratio prints. A holder of Shinhan or Hana knows the ceiling and has to wait for the decision. The premium between KB at one times book and Shinhan in the high 0.8s is the price of that certainty.
For completeness, the numbers KB is paying out from.
First-half 2026 net income was ₩3.93tn. The split was ₩1.92tn in the first quarter and ₩2.01tn in the second. Full-year 2025 was ₩5.84tn. On the first-half pace, the group is earning roughly 12.5% on equity. That's solid for a deposit-funded bank in a low-growth economy. But it is not the kind of return that justifies a premium to book on its own.
The revenue mix explains why. Net interest income was ₩3.14tn in the second quarter, down from ₩3.33tn in the first. Fee income rose to ₩1.60tn from ₩1.36tn. Credit-loss provisions were ₩520bn, roughly flat. The bank half of the business is treading water. The securities and card halves are growing. That's a fine business, but it isn't one whose earnings alone put the shares at book.
At ₩172,000 the shares trade near 7.8 times annualised first-half earnings. On that measure KB looks like any other Korean bank. On book, it doesn't. The gap between the two is the rule.
The premium rests on the CET1 surplus, and there are three ways the surplus shrinks.
The first is the regulator. Korea's Financial Supervisory Service sets the capital rules. It has warned banks in the past against distributing capital too aggressively. The supervisor could raise the effective floor or ask banks to hold more against household credit. Then KB's 13% threshold stops producing a surplus. The company needn't change a word of its plan.
The second is asset growth. Total assets rose to ₩866.9tn at the end of June from ₩797.9tn at the end of 2025. That's an increase of nearly 9% in six months. Risk-weighted assets grow with them. A bank that expands its loan book that fast will see its CET1 ratio fall unless earnings keep pace. KB has been funding that growth partly with hybrid capital. This counts toward some ratios but not toward CET1.
The third is the ROE-linked change management floated in July. Tying returns to return on equity instead of to surplus capital might sound like a step up. It's also a step back toward discretion. ROE is a result the board can interpret rather than a ratio the regulator computes. If the rule becomes a target, the reason KB trades above its peers weakens.
The third-quarter results, due in late October, will print the September CET1 ratio. Above 13.5% keeps the second-half formula producing surplus. Below it, the ₩180bn of flexible second-half capacity becomes the whole second-half return. The market will have to decide whether the premium was for a rule or for a year.
Beyond that, watch for a revised value-up plan filing. If KB replaces the CET1 formula with an ROE framework, that filing will be titled as a corporate value-up plan (기업가치제고계획) on DART. The details of what replaces the 13% line matter more than the headline ratio it promises.
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.