This study analyzes the impact on the Korean stock market of the inter-Korean summits in 2000, 2007, and 2018 and the North Korea–United States summit in 2018 using the event study methodology. Three portfolios, which have high exposures to North Korea risks are constructed: stocks related to Kaesong Industrial Complex (KS portfolio), stocks related to inter-Korean economic cooperation (IEC portfolio), and stocks related to the defense industry (DEF portfolio). Empirical analysis show that the cumulative abnormal returns (CARs) of KS, IEC, and DEF portfolios react positively or negatively to each summit. These results imply that peace does not simply play a role in boosting stock prices and that the stock price reflects all available information related to the summits, including the process and agreement of the summits’ discussion and political context. The robustness test (performed by changing the event day to the announcement rather than the agreement) shows that KS and IEC portfolios reflect positive expectation and that the DEF portfolio reflects negative expectation in the financial market. Although each CAR pattern varies, it is true that the stock price reflects all available information of summits swiftly. In other words, our paper shows that the efficient market hypothesis holds in the Korean stock market.