This paper uses account-level transaction data in Korea’s index options and futures to examine option trading skills by different types of investors. We first investigate how common option trading strategies are used. We find that (i) retail investors, both domestic and foreign, are more likely to hold naked option positions, while institutional investors are more likely to use complicated strategies; (ii) volatility trading is used more often than the other classic options strategies; (iii) a small number of accounts, both institutional and retail, generate large volumes of trades using sophisticated and well hedged positions. Then we examine the association between trading strategies and account performance. Our results show that (i) foreign investors are similar to domestic investors; (ii) for both retail and institutional investors, those using volatility and sophisticated strategies outperform their peers, and those using naked options underperform; (iii) volatility traders mainly gain from selling volatilities although subject to large downside risk. Our findings suggest that skilled options traders use volatility and complicated strategies, but informational advantage and country domicile are less important.