[Individual investor trading results in systematic and economically large losses. Using a complete trading history of all investors in Taiwan, we document that the aggregate portfolio of individuals suffers an annual performance penalty of 3.8 percentage points. Individual investor losses are equivalent to 2.2% of Taiwan's gross domestic product or 2.8% of the total personal income. Virtually all individual trading losses can be traced to their aggressive orders. In contrast, institutions enjoy an annual performance boost of 1.5 percentage points, and both the aggressive and passive trades of institutions are profitable. Foreign institutions garner nearly half of institutional profits.]

This study uses a Vector Autoregressive (VAR) model to examine interdependencies among institutional investors, big individual investors, and small individual investors, and the effects of their trading on stock returns on the Taiwan Stock Exchange (TSE). The results imply that, during the sample period, big individual investors are the most well informed players; their trading affects not only stock returns but also small individual investors. Small individual investors are not well informed and are slow learners. Their orders to trade tend to provide liquidity to institutional and big individual investors, but there is no compensation for their liquidity services. We find that institutional investors follow neither positive-feedback nor negative-feedback trading strategies. Overall, the responses to shocks, except for those of small individual investors, decay quickly, indicating that the TSE can absorb shocks quickly and efficiently. Our analysis implies that small individual investors would be better off institutionalizing their investment decisions (e.g., by investing in mutual funds).

Using data on all employees at listed companies in Taiwan, we find that the bias toward employer stocks is generic to individual investor decision making, but not limited to retirement plans. Seventy-one percent of the sample employees invest in employer stocks and employer stocks make up on average 47% of employee equity portfolios. The underdiversification resulting from the bias toward employer stocks is very costly. Holding current portfolio risk constant, employees forego 4.89% per annum in raw returns by investing in employer stocks, which represents 39.74% of their average 1998 salary income. Our findings have important implications for social security reform and retirement account management.

Rational models claim “trading to learn” explains widespread excessive speculative trading and challenge behavioral explanations of excessive trading. We argue rational learning models do not explain speculative trading by studying day traders in Taiwan. Consistent with previous studies of learning, unprofitable day traders are more likely than profitable traders to quit. Consistent with models of overconfidence and biased learning (but not with rational learning), the aggregate performance of day traders is negative; 74% of day trading volume is generated by traders with a history of losses; and 97% of day traders are likely to lose money in future day trading. Received: March 4, 2019; Editorial decision: May 16, 2019 by Editor: Jeffrey Pontiff.

Data from the Taiwan Stock Exchange identify the originator of each submitted order, and there are no designated dealers or specialists. We study marketable order imbalances, i.e., the net order flow resulting from trades that demand immediacy. We distinguish imbalances by trader type (individuals, domestic institutions, foreign institutions) and by the usual size of each trader's order. Day-to-day persistence in order imbalance is strongest for small foreign institutions and weakest for large individual traders. Such persistence emanates both from splitting orders over time and from herding, and there is little evidence that aggregate price pressures from such persistence last beyond a trading day, indicating that de facto market making is quite effective. We attempt to discern which types of traders are de facto liquidity providers, which are likely to be informed, and which trade for liquidity reasons. The evidence indicates that all trader classes are successful market makers, large domestic institutions conduct the most informed trades, and large individuals are noise or liquidity traders.

IPO auctions, which provide an impartial way of determining IPO pricing and share allocations, offer a natural setting for examining whether institutional investors possess private information, and for measuring how valuable their information is. Analyzing detailed bidding data from Taiwan’s discriminatory (pay-as-bid) auctions, we find that, relative to retail investors, institutional investors tend to bid higher in auctions when IPO shares are more valuable, and that underpricing is larger in auctions with relatively higher institutional bids. These results imply that institutional investors are better informed about IPO value, and that they obtain higher information rents when they bid higher relative to retail investors. We estimate the value of institutional investors’ private information to be worth about 8.68% of return, which is the extra rate of return they command on their informational advantages over retail investors.

Although dividend clientele have been studied over several decades, their existence remains controversial. We study the interaction of dividends and taxes by exploiting a unique dataset from Taiwan, where the capital gains tax is zero. We find strong evidence of a clientele effect. Agents subject to high rates of taxation on dividends tend to hold stocks with lower dividends and sell (buy) stocks that raise (lower) dividends. Agents in lower tax brackets behave in the opposite manner. After legalization of repurchases in 2000, firms with higher concentrations of more heavily taxed shareholders were more apt to begin repurchase programs.

Individual investor trading results in systematic and economically large losses. Using a complete trading history of all investors in Taiwan, we document that the aggregate portfolio of individuals suffers an annual performance penalty of 3.8 percentage points. Individual investor losses are equivalent to 2.2% of Taiwan's gross domestic product or 2.8% of the total personal income. Virtually all individual trading losses can be traced to their aggressive orders. In contrast, institutions enjoy an annual performance boost of 1.5 percentage points, and both the aggressive and passive trades of institutions are profitable. Foreign institutions garner nearly half of institutional profits.