在大马股市里，投资者按照特定主题轮番炒作是屡见不鲜的。举例而言，当大宗商品如原油、原棕油或黄金期货大幅上涨时，营运长年累月经历亏损的相关公司股价也随之大幅波动。
换句话说，短期内，投资者往往把资金投放在受欢迎（popular）而非有盈利能力（profitable）的股项。有些投资者在相关股项上涨尾声才加入时，往往会被套或面对亏损。
2020年，许多医疗保健相关的股票受益于疫情，成了众多投资者的宠儿，股价涨幅凌厉。然而，这些股票当中不乏长期经历亏损或处于技术超买的区间却屡创股价新高。这是不是意味著基本面和技术面分析失灵？投资者情绪的羊群行为（herding behavior）有助于解释这种现象。
羊群效应
股票市场的羊群行为可以归纳为三大类。当投资者对公开的信息如某上市公司宣布投入手套生产和疫苗相关业务做出同样的反应时，基于信息的羊群效应（information-based herding）就发生了。
基于名望的羊群效应（reputation-based herding）是由受人追捧且有影响力的投资者或主要交易公司采取特定的交易立场而引起的。比方说，当一名知名投资者发表自己持有某一支股票时，一般投资者会跟随争相购买那支股票。
当某些情况促使大型机构基金经理获利时（通常是为了在年终报告前保持基金回报率），就会发生基于回酬的羊群行为（compensation-based herding）。这些行为在某些股票或受欢迎的机构组合投资领域产生了巨大的交易量，促使那些观察者迅速做出反应。
根据大马交易所数据显示，2020年首7个月，新开设的中央存票户头（CDS）高达21万8000个相较前年同期的9万7000个翻倍增加。蜂拥进入股市的投资者使到开设户头需要耗上2至3个月的时间。截至去年最后一个交易日，外国投资者净卖出的248亿令吉股票分别由散户投资者和本地机构投资者吸纳。散户投资者甚至超越了本地机构投资者净买入总值138亿令吉股票，成为大马股市最大买家。
除此之外，散户投资者参与度超过30%，高于10年均值为24%。综上所述，面临外国投资者大量卖出股票的浪潮下，散户投资者可谓大马股市的“造王者”。
有鉴于散户投资者在金融市场参与度大大提高，考究散户投资者情绪如何牵动金融市场尤为重要。一年之计在于春，投资者不妨在新的一年里多学习有关投资理论，理性地进行投资。祝愿大家“牛”赚股市！
《投资者情绪“牛”转股市》（Bull market is made of bullish investor sentiment）原文：
It is phenomenal for investors to leverage on special investment themes in the Malaysian stock market for profits. For example, when commodity futures, such as crude oil, crude palm oil or gold, rise sharply, so do the shares of companies despite running operating losses for years.
In other words, in the short term investors endeavor to invest in popular stocks rather than profitable ones. Some investors who join any rallies at the final stage, often get caught and experience losses.
In 2020, many health care-related stocks benefited from the epidemic and became the darling of many investors, with their share prices rising sharply. However, some of these stocks have been losing money for a long time or are in technically overbought territory while hitting record high level. Does this mean that fundamental and technical analysis is futile to explain stock prices? Herding behavior, a subcategory of investor sentiment might offer a good explanation for this phenomenon.
Herding behavior in the stock market can be classified into three categories. Information-based herding occurs when investors react to public information, such as the announcement of a publicly traded company's involvement in glove production and vaccine-related businesses. Reputation -based herding occurs when a popular and influential investor or major trading firm takes a particular trading stance. For instance, when a well-known investor announces that he owns a stock, average investors follow suit and rush to buy that stock.
Herding behavior based on compensation occurs when certain circumstances motivate large institutional fund managers to make a profit, usually to preserve the fund's return until year-end reports. These actions generate huge volumes in certain stocks or popular institutional portfolios, prompting those observers to react quickly.
The number of new central depositing accounts (CDS) opened in the first seven months of 2020 doubled from 97,000 in the same period a year earlier, according to data from the Bursa Malaysia. As many investors flocking into the stock market, it can take two to three months to open a trading account. As of the last trading day last year, RM24.8 billion of shares sold by foreign investors were taken up by retail investors and local institutional investors.
Retail investors even outstripped local institutional investors by buying of RM13.8 billion worth of shares to become the biggest buyers on the Malaysian stock market.
In addition, retail investor participation soared past 30 percent, up from a 10-year average of 24 percent. To sum up, retail investors have been the kingmakers of the Malaysian stock market amid a wave of heavy selling by foreign investors.
Given the increased participation of retail investors in financial markets, it is particularly important to understand how retail investor sentiment affects financial markets. As the saying goes, the whole year's work depends on good planning in spring, investors may wish to learn more about investment theory in the New Year, and thus making rational investment decisions. Wishing everyone to prosper in a bull year!
