中文：

中小投资者是指投入股市资金或购买股票数量相对较少的投资者。他们通常是由个人或小型机构组成的，相对于大型机构投资者来说，他们的投资规模和影响力都比较小。

中小投资者在股市中扮演着重要的角色，因为他们数量众多，且具有一定的投资理财需求。然而，由于资金规模和信息不对称等因素，他们往往面临着较高的投资风险和较低的投资收益。因此，保护中小投资者的权益和利益，是维护股市稳定和健康发展的重要保障。

为了保护中小投资者的权益和利益，监管机构和证券交易所制定了一系列的相关政策和规定，例如信息披露制度、投资者教育计划、交易费用减免等。这些政策和规定旨在提高市场透明度、降低投资风险、增加中小投资者的收益机会等方面，以促进市场的公平、公正和健康发展。

总的来说，中小投资者是股市中不可或缺的一部分，他们的权益和利益需要得到充分保障。只有这样，才能让市场更加公平、公正和健康发展。

英文：

Small and medium-sized investors refer to investors who invest relatively small amounts of funds in the stock market or purchase a relatively small number of shares. They are usually composed of individuals or small institutions, and compared to large institutional investors, their investment scale and influence are relatively small.

Small and medium-sized investors play an important role in the stock market, because they have a large number of investors and have certain investment and financial needs. However, due to factors such as funding size and information asymmetry, they often face high investment risks and low investment returns. Therefore, protecting the rights and interests of small and medium-sized investors is an important guarantee for maintaining the stability and healthy development of the stock market.

To protect the rights and interests of small and medium-sized investors, regulatory agencies and stock exchanges have formulated a series of relevant policies and regulations, such as information disclosure systems, investor education plans, trading fee reductions, etc. These policies and regulations aim to increase market transparency, reduce investment risks, increase the yield opportunities of small and medium-sized investors, etc., so as to promote fairness, justice and healthy development of the market.

In general, small and medium-sized investors are an indispensable part of the stock market, and their rights and interests need to be fully protected. Only in this way can the market be more fair, just and healthy.