Celltrion's board approved buying 524,384 of its own shares on the open market between September 1 and November 30, an estimated ₩100.0bn based on the ₩190,700 close the day before the resolution. That is 0.23% of the 232.6m shares outstanding and about 0.2% of a ₩43.7tn market capitalisation, but close to 10% of FY2025 net income of ₩1.03tn. The company states it plans to cancel the entire amount, which is the part worth noting, because Korean companies frequently buy without ever cancelling. It has already retired 9,598,977 shares so far in 2026, leaving 3,983,455 in treasury. The cost is not fixed: ₩100.0bn is a price-based estimate and the actual spend moves with the market. NH Investment & Securities is the executing broker, and the filing shows ₩4.46tn of headroom under the distributable-profit limit.