The study by Barber, Lee, Liu, and Odean examines the trading behavior of individual investors in Taiwan's stock market and finds that individual investors incur significant and economically large losses due to their aggressive trading strategies. Using a comprehensive dataset covering all transactions from 1995 to 1999, the authors document that individual investors suffer an annual performance penalty of 3.8 percentage points, equivalent to 2.2% of Taiwan's GDP or 2.8% of total personal income. These losses are primarily attributed to trading losses, commissions, transaction taxes, and market-timing losses. In contrast, institutions enjoy an annual performance boost of 1.5 percentage points, with both their passive and aggressive trades being profitable. The study also highlights that foreign institutions contribute nearly half of the institutional profits, representing a wealth transfer from Taiwanese individual investors to foreigners. The findings suggest that individual investors are at a disadvantage when trading against professional institutions and that their aggressive trading strategies are a major source of their losses.The study by Barber, Lee, Liu, and Odean examines the trading behavior of individual investors in Taiwan's stock market and finds that individual investors incur significant and economically large losses due to their aggressive trading strategies. Using a comprehensive dataset covering all transactions from 1995 to 1999, the authors document that individual investors suffer an annual performance penalty of 3.8 percentage points, equivalent to 2.2% of Taiwan's GDP or 2.8% of total personal income. These losses are primarily attributed to trading losses, commissions, transaction taxes, and market-timing losses. In contrast, institutions enjoy an annual performance boost of 1.5 percentage points, with both their passive and aggressive trades being profitable. The study also highlights that foreign institutions contribute nearly half of the institutional profits, representing a wealth transfer from Taiwanese individual investors to foreigners. The findings suggest that individual investors are at a disadvantage when trading against professional institutions and that their aggressive trading strategies are a major source of their losses.