Note(s): This table reports interrupted time-series (ITS) regression results for the long-run effects of offshore Korean equity index derivatives on KOSPI 200 market share. Models 1 and 2 use Volume Share as the dependent variable, while Models 3 and 4 use Value Share. Volume Share is defined as KOSPI 200 trading volume divided by the combined trading volume of KOSPI 200, KOSDAQ 150, and KRX 300. Value Share is defined analogously using trading value. Post is an indicator equal to one for trading days on or after the offshore listing event and zero otherwise. Trend and Post × Trend are scaled by 100 trading days. Return and VKOSPI are included as control variables in Models 2 and 4. Newey-West standard errors with five lags are used. t-statistics are reported in parentheses. ***, **, and * denote significance at the 1%, 5%, and 10% levels, respectively