Abstract: Presumably, everyone knows that they will invest some spare money in their hands, and stocks are one of the most risky returns. If you want to invest in stocks, you must have heard the concept of GEM index. Growth enterprise market index was officially compiled and published by Shenzhen Stock Exchange on June 1st, 21, with the purpose of reflecting the growth enterprise market more comprehensively. Maybe many people still don't know the GEM index, so let's talk about the GEM index. What does GEM index mean? How to calculate GEM index

GEM index is the subject matter of Shenzhen Stock Exchange to provide investors with more tradable index products and financial derivatives, promote index fund products and enrich the variety of products in the securities market. It was officially compiled and released on June 1, 21. The compilation of this index refers to the compilation methods of Shenzhen Component Index and Shenzhen 1 Index and international practices (including total income index and pure price index). That is, the starting date is taken as a benchmark, and the stock price of the day is calculated one by one according to the circulating market value of all the stocks on the GEM, and then the weighted average is compared with the "benchmark" of the opening day. At this point, the GEM index, Shenzhen Stock Exchange Index and Small and Medium Board Index * * * together constitute the core index reflecting the operation of listed stocks in Shenzhen Stock Exchange.

the significance of the growth enterprise market index

the launch of the growth enterprise market index marks that the growth enterprise market has entered a new development period after its smooth start and that a multi-level capital market index system has been established.

first of all, it highlights the operational characteristics of GEM as a relatively independent market level, and enhances its influence and service capacity;

Secondly, comprehensively and objectively reflect the overall price changes and trends of GEM stocks, and provide authoritative reference indicators for investors;

Third, it provides a new target for the development of index-linked products, so that investors can invest in the Growth Enterprise Market more effectively and share the growth fruits of listed companies on the Growth Enterprise Market.

Characteristics of Growth Enterprise Market Index

Firstly, the sample selection of the index is based on two indicators, namely "market share of circulating market value" and "market share of transaction amount", which reflects the characteristics of high circulating market value and active transaction in Shenzhen.

Secondly, the index calculation takes the "accurate value" of the "freely circulating share capital" of the sample shares as the weight, which eliminates the leverage effect caused by the share structure and makes the index performance more sensitive, accurate and true.

finally, the sample stocks of the index are adjusted once every quarter to reflect the rapid growth of the Growth Enterprise Market.

Selection criteria of GEM index

From the compilation scheme of GEM index, there are five shortlisted criteria for index sampling:

1. A shares listed and traded on the GEM of Shenzhen Stock Exchange;

2. Have a certain listing date (usually three months);

3. The company has no major violations and no major problems in its financial report in the last year;

4. The company has no abnormal operation and no major losses in the last year;

5. There was no abnormal fluctuation in the stock price during the investigation period. The initial constituent stocks of the GEM index are all GEM stocks that have been included in the calculation of the Shenzhen Composite Index on the date when the index is released.

6. Before the number of index samples is less than 1, the newly listed GEM stocks will be included in the index calculation on the 11th trading day after listing; After the number of index samples reaches 1, the number of samples is locked to 1, and the sample stocks are regularly adjusted according to the regular sample adjustment rules.

selection method

gem index selects 1 sample stocks from gem stocks to reflect the operation of gem market.

The initial constituent stocks are all GEM stocks that have been included in the calculation of Shenzhen Composite Index on the release date.

Before the sample of GEM index is less than 1, the newly listed GEM stocks will be included in the index calculation on the 11th trading day after listing.

When the sample number of GEM index is over 1, the sample number will not increase any more. In the future, it is necessary to sort the shortlisted stocks and select the constituent stocks.

The sampling index of GEM is the proportion of the average circulating market value and the average transaction amount in a period of time (generally six months). When selecting samples, first calculate the proportion of the short-listed stocks' average circulating market value to the GEM market and the average transaction amount to the GEM market, and then average the above indicators with a weight of 2: 1, and the calculation results are sorted from high to low. After referring to the corporate governance structure, operating conditions and other factors, the constituent stocks of the GEM index are selected according to the buffer technology.

gem index adjustment rules

the gem index will be adjusted quarterly after the sample is over 1, and the implementation time is scheduled for the first trading day of January, April, July and October every year, and the adjustment plan is usually announced on the first trading day of the second complete trading week in January before the implementation date.

The regular adjustment method of the sample of constituent stocks is to comprehensively rank the short-listed stocks according to the weighted ratio in the sampling method, and then select stocks according to the following principles:

1. Non-original constituent stocks ranked within 7% of the sample number are selected in order;

2. The original constituent stocks ranked within 13% of the sample number shall be reserved in order;

3. The number of sample stocks adjusted each time shall not exceed 1% of the total number of samples.

calculation method of growth enterprise market index

The calculation method of growth enterprise market index is weighted average calculation method. Based on the starting date and the circulating market value of all the stocks on the growth enterprise market, the stock prices of that day are calculated one by one, and then the weighted average is compared with the "benchmark" on the opening day.

GEM index is compiled by Paige's weighting method, and it is calculated in real time day by day by using the following formula:

Real-time index = closing index of the previous trading day * ∑ (component stocks' weight at the closing price of the previous trading day)/∑ (component stocks' weight at the closing price of the previous trading day)

In the above formula, "component stocks" refers to the stocks included in the index calculation range and "component stocks' weight". The product in the sub-item is the real-time free circulation market value of the constituent stocks, and the product in the parent item is the free circulation market value of the constituent stocks at the closing of the previous trading day. ∑ refers to the summary of the free circulation market value of the constituent stocks included in the index calculation.

the opening index is calculated by the opening price of the constituent stocks in call auction after the opening of each trading day, and then the real-time index is calculated by the real-time transaction price of the constituent stocks during the trading hours, and the closing index is calculated by the closing price of the constituent stocks after the closing.

if there is no transaction for the constituent stocks on that day, the closing price of the previous trading day shall be taken.

if the trading of constituent stocks is suspended, the latest transaction price shall be taken.

Free circulation refers to the actual number of tradable shares of listed companies, which is the number of tradable shares excluding "unrestricted shares held by the following three types of shareholders with a shareholding ratio of more than 5% and their concerted actions": 1. State-owned (legal person) shareholders; 2. Strategic investors; 3. The founder, family or senior management of the company.

regular adjustment of gem index

the adjustment calculation of gem index is to adjust the relevant data items in the real-time calculation formula of index separately or simultaneously according to different situations before the market opens.

1. Adjusting the range of constituent stocks

means adjusting the summary range of ∑ in sub-items and parent items, and including (or excluding) a stock in the index calculation, including:

1. Before the sample of GEM index is less than 1, newly listed GEM stocks will be included in the index calculation on the eleventh trading day after listing;

2. The sample of constituent stocks is adjusted regularly;

3. If the listing of constituent stocks is suspended or terminated, the corresponding constituent stocks will be removed from the index calculation from the date of suspension or termination of listing, and the sample vacancies caused by the removal will be made up during regular adjustment;

4. For newly listed stocks, if the average circulating market value in the first five trading days ranks within the top 1% in the sample space of index constituent stocks, they will be quickly selected into the constituent stocks after 15 trading days, and the original constituent stocks with the smallest market value will be excluded from the index;

5. If the trading of sample companies of constituent stocks may be suspended or terminated due to major irregularities (such as major fraud in financial reports), they will be eliminated from the index samples in time according to the decision of the index expert committee, and the sample vacancies caused by the elimination will be filled during regular adjustment;

6. In case of acquisition, merger or division of constituent stocks, it shall be handled according to special provisions.

second, adjust the closing price of a constituent stock in the parent item on the previous trading day

The GEM index is divided into a total income index and a price index.

for the total income index, when the listed company conducts dividend distribution, share offering, share allotment, transfer or other ex-dividend situations, the date of record closing price of the constituent stock in the parent item will be updated to the ex-dividend reference price on the ex-dividend date. The ex-dividend reference price is based on the data released by Shenzhen Stock Exchange.

for the price index, cash dividends will not be ex-dividend adjusted on the ex-dividend date, and the other methods are the same as the total income index.

3. Adjust the weight of a constituent stock in the sub-item and the parent item, that is, the free circulation

1. The constituent stock company distributes the rights and interests, and on the day of stock offering and transfer of rights, the weight of the corresponding constituent stock is revised according to the actual number of stock offering and transfer. When a constituent stock company issues additional shares or shares, it shall revise the weight of the constituent shares on the listing date of its new shares; When a constituent stock company carries out debt-to-equity swap, share repurchase and warrant exercise, it will implement amendments on the trading day next to its announcement date.

2. In the case of changes in the free circulation weights caused by non-corporate behaviors such as the expiration of the restricted sale of new shares issued by the promoters, the lifting of the ban on off-line allotment of shares, the lifting of the ban on the allocation of shares to major shareholders or strategic investors in private placement, the increase of holdings by major shareholders, and the decrease of holdings by major shareholders, in the first trading day of January and July of each year, centralized periodic corrections are made according to the shareholding data published in the latest periodic reports and temporary announcements of listed companies.

maintenance and release of growth enterprise market index

the growth enterprise market index is authorized by Shenzhen Stock Exchange and entrusted by Shenzhen Securities Information Co., Ltd. to prepare, maintain and release. The real-time market is released along with the real-time securities market through the real-time satellite broadcasting system of Shenzhen Stock Exchange. Index component stock information is released through the websites of Shenzhen Stock Exchange and Juchao Index.

index management

The Shenzhen Stock Exchange entrusts the Index Division of Shenzhen Securities Information Co., Ltd. to design and manage the GEM index.

GEM index belongs to the assets of Shenzhen Stock Exchange. Without the written permission of Shenzhen Stock Exchange or Shenzhen Securities Information Company, no unit or individual may track or trade the index or use it as the evaluation benchmark.