自2001年9月我国发行第一只开放式证券投资基金以来，中国的证券投资基金市场现已成长为全球第四大开放式公募基金市场。与庞大市场规模相对应的是持续的居民参与热情，截至2021年底，我国个人基金投资者人数已经超过7.2亿人。然而，与居民高涨的基金投资热情相对应的确是惨淡的投资收益。市场的整体波动固然是造成大多数投资者亏损的原因之一，但个人投资者在交易中表现出的种种有限理性交易行为才是导致亏损的核心原因。因此，本文以行为金融学理论为基础，通过研究基金个人投资者的有限理性交易行为，探索这些交易行为背后的深层次驱动因素，不仅有利于政府监管部门制定更好的投资者保护措施，也有利于行业相关机构更好的了解客户、服务客户，促进公募基金行业实现高质量发展。

关于个人投资者交易行为的研究，虽然当前学界取得了一定的成果，但是由于数据可用性的限制，尤其可用的基金个人投资者交易数据仍十分稀缺，这些研究当前仍主要集中在发达市场中的股票个人投资者交易行为方面。尽管基金个人投资者在交易中表现出很多与股票个人投资者相似的有限理性行为，但二者同样存在很多如处置效应上的显著差异（Chang et al., 2016）。因此，十分有必要对基金个人投资者的交易行为进行单独的研究分析。此外，对于个人投资者交易行为的分析，以往的研究多从窄框架下的逐股分析视角（Stock-by-Stock）进行展开，考虑单只股票本身的盈亏状态对投资者交易行为的影响，忽视组合整体以及组合内部其它股票对投资者交易某只股票的影响。虽然这种分析思路简化了关于个人投资者行为研究的难度，但距离投资者真实的决策过程仍有一段距离。所以有必要从投资组合的研究视角出发，重新审视个人投资者的交易行为。本研究利用某互联网基金销售公司提供的20万名基金个人投资者在2018年至2019年两年间的交易数据，从基金个人投资者同时赎回多只基金、排名效应以及再购买三个方面分析了组合视角下的基金个人投资者有限理性交易行为。

在基金个人投资者同时赎回多只基金方面，本研究主要探究了个人投资者交易行为中的享乐编辑假说。首先在直接层面上检验了基金个人投资者是否更愿意同时实现亏损、分散实现盈利。其次，本研究在间接层面上分析享乐编辑假说对投资者赎回盈利倾向的影响。如果享乐编辑假说存在，个人投资者会对不同基金上的心理账户进行享乐编辑，因此组合整体或组合内其它基金的状态必然会影响投资者赎回盈利的倾向性。

在排名效应方面，本研究首先验证了基金个人投资者的赎回行为中存在排名效应，即投资者更愿意赎回排名最高和最低的基金。其次，检验多种排序方式下，排名效应的存在性问题。再次，基于收益排序和非收益排序的结果，分析排名效应产生的原因。

在再购买交易方面，本研究首先检验相比于之前赎回时的亏损基金，投资者是否更愿意再次申购之前赎回的盈利基金。其次，分析近因效应对投资者再购买倾向的影响，探索近期发生的多种交易情形对投资者再购买行为的影响。最后分析近期效应的强度如何影响投资者的再购买交易，即检验个人投资者的再购买倾向是否会随着近期交易其它基金次数的增加而减少。

本文的主要结论包括：

第一，投资者组合中不同基金之间的心理账户并不是孤立的，基金个人投资者会通过编辑心理账户来达到价值最大化。在交易中，个人投资者更倾向于分散实现盈利并聚集实现亏损。此外，整体投资组合的盈利状态会削弱投资者在单只基金上的处置效应，同时赎回多只基金时，当天赎回组合中的其它基金同样会影响投资者的处置效应。

第二，基金个人投资者的赎回交易存在显著的排名效应，这种现象不仅发生在基于收益的排序方式下，同样存在于非收益排序方式之中。当一只基金拥有的最好或最差排名次数越多时，其被个体投资者赎回的可能性越强。

第三，基金个人投资者更可能再次申购之前赎回过的盈利基金。如果近期交易过其它基金，那么基金个人投资者再购买的倾向将会降低，且近期交易其它基金的次数越多，投资者再购买的可能性越低。

本文可能的创新之处体现在：

第一，相比于传统的单个股票分析视角，从投资组合角度来探究个人投资者交易行为的研究目前仍相对稀少，因此本文的研究有助于为该方向提供更多的证据。

第二，为享乐编辑假说提供了来自实证上的相关证据，同时本文在关注投资组合整体盈亏状态的基础上，进一步考虑了组合中同时交易的其它基金对赎回盈利倾向的影响。

第三，将基于收益排序下的排名效应拓展到多种排序方式，并提出个人投资者的排名效应不仅是由于凸显理论导致的，同时也会受到启发式思考的影响，为分析个人投资者的有限理性决策方式做出了贡献。

第四，全面分析了近因效应对基金个人投资者再购买交易的影响。不仅考虑了近期是否发生过赎回交易这一种情形，还考虑了近期是否发生申购交易等多种情形。此外本研究使用近期交易发生的次数来衡量近因效应的强度，进一步分析近因效应对再购买行为的影响，为个人投资者的再购买行为提供更为深入的研究证据。

Since China launched its first mutual fund in September 2001, the mutual fund market has now grown into the fourth largest market in the world. Corresponding to the huge market size is the enthusiasm of residents to participate. As of the end of 2021, the number of individual fund investors in China has exceeded 720 million. However, most individual investors do not have a good investment return. Although significant market fluctuations are one of the reasons for most investors' losses, the various behavioral biases of individual investors in trading are the core reason for poor returns. Therefore, based on the theory of behavioral finance, this paper studies the limited rational trading behaviors of individual fund investors and explores the driving factors of these trading behaviors, which is not only conducive to the government regulatory authorities to formulate better investor protection policies, but also conducive to the relevant institutions of the industry to better understand and serve customers, and promote the mutual funds industry to achieve high-quality development.

    Although there have been some achievements in the academic community regarding the research on the trading behavior of individual investors, due to limitations in data availability, especially available fund individual investor trading data is still very scarce. These studies are currently mainly focused on the trading behavior of stock individual investors in developed markets. Although individual fund investors show many behavioral deviations similar to those of individual stock investors in trading, there are also significant differences between them in terms of disposal effect (Chang et al., 2016). Therefore, it is very necessary to conduct separate research and analysis on the trading behavior of individual investors in funds. In addition, previous research on the trading behavior of individual investors has mostly focused on a stock-by-stock analysis perspective, considering the impact of the profit and loss status of a single stock on investors' trading behavior, while neglecting the impact of the overall portfolio and other stocks within the portfolio on investors' trading of a particular stock. Although this analytical approach simplifies the difficulty of studying individual investor behavior, there is still a distance from the true decision-making process of investors. So, it is necessary to re-examine the trading behavior of individual investors from the perspective of portfolio. This study analyzes the limited rational trading behavior of individual fund investors under the portfolio perspective using the trading data of 200,000 individual fund investors provided by an Internet fund sales company for two years from 2018 to 2019, in terms of three aspects: simultaneous redemption of multiple funds by individual fund investors, rank effect, and repurchase.

In terms of simultaneous redemptions of multiple funds by individual fund investors, this study focuses on the impact of the hedonic editing hypothesis on individual investors' trading behavior. First of all, it tests whether individual investors are more likely to integrate losses and segregate gains. Secondly, this study indirectly analyzes the influence of hedonic editing hypothesis on investor disposition effect. If the hedonic editing hypothesis exists, individual investors will perform hedonic editing on mental accounts on different stocks, so the overall status of the portfolio or other funds within the portfolio will inevitably affect the disposal effect of investors.

In terms of ranking effect, this study first verified the existence of ranking effect in the redemption behavior of individual fund investors, that is, they are more likely to redeem the highest and lowest ranking funds. Secondly, this paper tests the existence of ranking effect under various ranking methods. Finally, based on the results of return ranking and non-return ranking, the causes of ranking effect are analyzed.

In terms of repurchase transactions, this study first tests whether investors are more likely not to repurchase funds previously redeemed for a loss. Secondly, the paper analyzes the influence of recency effect on investors' repurchase tendency, and explores the influence of various recent trading events on investors' repurchase behavior. Finally, this article analyzes how the strength of recent effects affects investors' repurchase transactions, which tests whether individual investors' repurchase intention will decrease with the increase of recent transactions in other funds.

The main conclusions of this paper include:

First, the mental accounts between different funds in the portfolio are not isolated, and individual fund investors will edit the different mental accounts to maximize the value. In trading, individual investors are more likely to diversify their gains and aggregate their losses. In addition, the overall profitability of the investment portfolio will weaken investors' disposal effect on a single fund, and when multiple funds are redeemed, the redemption of other funds in the portfolio on the same day will also affect investors' disposal effect.

Second, redemption transactions of individual investors in mutual funds have a significant ranking effect, which not only occurs in the return-based ranking way, but also in the non-return ranking way. The more times a fund has a best or worst ranking, the more likely it is to be redeemed by individual investors.

Third, individual fund investors are more reluctant to repurchase funds previously redeemed for a loss. If they have recently traded other funds, the individual investor will be less inclined to repurchase, and the more times they have recently traded other funds, the less likely the investor is to repurchase.

The contributions of this paper are as follows:

Firstly, compared to traditional stock-by-stock analysis, research on individual investor trading behavior from a portfolio perspective is still relatively scarce. Therefore, this study helps to provide more evidence for this direction.

Second, it provides empirical evidence for the hedonic editing hypothesis. At the same time, based on the overall portfolio return, this paper further considers the influence of other funds trading in the portfolio on the disposal effect.

Thirdly, the ranking effect based on return ranking is extended to more ranking methods, and it is proposed that the ranking effect of individual investors is not only caused by salience theory, but also influenced by heuristic thinking, which makes a contribution to the analysis of individual investors' limited rational decision-making methods.

Fourthly, it comprehensively analyzes the influence of recency effect on repurchase transactions of individual fund investors. It not only considers whether there has been a redemption transaction recently, but also considers whether there has been a purchase transaction recently. In addition, this study uses the frequency of recent transactions to measure the intensity of recency effect, further analyzes the influence of recency effect on repurchase behavior, and provides more research evidence for individual investors' repurchase behavior.