South Korean stock market rebounded on September 16, 2026, with KOSPI rising 1.37% and KOSDAQ up 0.44%, driven primarily by semiconductor stocks Samsung Electronics and SK Hynix. However, the rally was narrow—falling stocks outnumbered rising ones by nearly 2:1—and foreign investors continued net selling for a sixth consecutive day despite the index gains.
Korean stock market analysis from September 9, 2026 showing broad gains across AI-related sectors. KOSPI rose 1.40% and KOSDAQ jumped 2.28%, with strength spreading from AI data centers through optical communications, power cables, batteries, and semiconductors. Key gainers included battery material companies (SM Vattle +21.24%, LG Energy Solution, Samsung SDI) and optical communication firms (Mercury +30%) following Verizon's multi-billion dollar fiber optic supply contract with Corning.
Korean Stock Data API provides free, no-authentication access to 2,791 Korean ticker quotes with T+1 closing prices and DART regulatory filings including minute-level receipt timestamps. Data is refreshed daily as static JSON files with open CORS, supporting multiple languages and client libraries.