I. Overview of Securities There are two concepts of securities: broad and narrow. Securities in a broad sense include commodity securities, currency securities and capital security. Securities in a narrow sense are capital certificates. Commodity securities are documents that prove that the holder has the ownership or use right of commodities. Obtaining these securities is equivalent to obtaining the ownership of these commodities, and the owner's ownership of the commodities represented by these securities is protected by law. Commodity securities include bills of lading, waybills and warehouse receipts. Monetary securities refer to securities that enable the holder or a third party to obtain the right to claim money. Currency securities mainly include two types: one is commercial securities, mainly including commercial bills and commercial promissory notes; The other is bank securities, mainly including bank drafts, cashier's checks and checks. Capital security refers to the securities generated by financial investment or activities directly related to financial investment. The bondholders have the right to claim certain benefits from the issuer, including stocks, bonds and their derivatives such as fund securities and convertible securities. Capital security is the main form of securities, and securities in a narrow sense refer to capital security. In daily life, people usually refer to the narrow sense of securities-capital security directly as securities or even securities. Two. Classification of securities Securities can be classified according to different standards from different angles: (1) Classification of securities issuers According to different securities issuers, securities can be divided into government securities, government agency bonds and enterprise securities. Government bonds are usually bonds issued by the central government or local governments. Central government bonds, also known as national debt, are usually issued by the Ministry of Finance of a country. Local government bonds are issued by local governments and repaid with local taxes or other income. At present, except for special administrative regions, local governments at all levels in China are not allowed to issue bonds. Government agency securities are securities issued by approved government agencies, and China does not allow government agencies to issue bonds at present. Corporate securities are securities issued by companies to raise funds, which cover a wide range, including stocks, corporate bonds and commercial paper. In addition, among corporate bonds, securities issued by banks and non-bank financial institutions are usually called financial securities, among which financial bonds are particularly common. (2) Classification of marketable securities According to marketability, marketable securities are divided into marketable securities and priceless securities. Securities refer to the securities that can be sold quickly in the securities market when the holders need cash or want to convert their securities into cash. Such securities are the main investment targets of financial investors, including company stocks, corporate bonds, financial bonds, national debt, public bonds, warrants, warrants and so on. Unmarked securities refer to securities that holders of securities cannot or cannot sell quickly in the securities market when they need cash. Although this kind of securities can't or can't be sold quickly in the securities market, they all have the characteristics of less investment risk, certain investment income and being convertible into cash under certain conditions, such as time deposit certificates. (3) According to whether the securities are listed or not. According to whether securities are listed or not, securities can be divided into listed securities and unlisted securities. Listed securities, also known as listed securities, refer to the securities approved by the competent securities department, registered in the stock exchange, and qualified for public trading in the exchange. Unlisted securities, also known as unlisted securities and OTC securities, refer to securities that have not applied for listing or do not meet the listing conditions of stock exchanges. (4) According to whether the securities income is fixed or not. According to whether the income is fixed or not, securities can be divided into fixed income securities and variable income securities. Fixed-income securities refer to securities holders who can obtain fixed income within a specific period and know the amount and time of income in advance, such as fixed-interest bonds and preferred stocks. Variable income securities refer to securities whose income changes with the change of objective conditions. For example, the dividend income of common stock is uncertain in advance, but depends on the after-tax profit of the company. Another example is floating rate bills. Generally speaking, variable income securities have higher returns and greater risks than fixed income securities, but under the condition of inflation, the risks of fixed income securities are far greater than those of variable income securities. (5) According to the regions and countries where securities are issued. According to different regions or countries, securities can be divided into domestic securities and international securities. Domestic securities are securities issued by a country's domestic financial institutions, companies, enterprises, other economic organizations or the government in the domestic capital market at the face value of its own currency. International securities are securities issued by a government, financial institutions, companies or international economic institutions in the international securities market with the face value of other countries' currencies, including international bonds and international stocks. (VI) Classification by means of securities issuance According to different means of issuance, securities can be divided into public securities and private securities. Public offering of securities refers to the public offering of securities by issuers to unspecified public investors through intermediaries, with strict examination and approval and publicity system. Private placement securities are securities issued to a few specific investors, and their examination conditions are relatively relaxed, and there are fewer investors, so the publicity system is not adopted. Investors in private placement securities are mostly institutional investors who have a specific relationship with the issuer, as well as internal employees of issuing companies and enterprises. (VII) Classification according to the nature of securities According to the economic nature of securities, they can be divided into two categories: basic securities and financial derivative securities. Stocks, bonds and investment funds are all basic securities. They are the most active investment tools, the main trading objects in the securities market, and the focus of securities theory and practice research. Financial derivative securities refer to securities trading varieties derived from basic securities, mainly including financial futures and options, convertible securities, depositary receipts, warrants and so on. (8) According to the different property rights set by securities, securities can be divided into: (1) securities with equal rights, such as stocks; (2) bills of lading, warehouse receipts and other securities with certain property rights; (three) bonds, bills of exchange, promissory notes, checks and other securities with certain creditor's rights. (9) According to the different ways of securities transfer, it can be divided into: (1) registered securities, that is, securities with the name of the securities owner, such as registered bills and stocks. Registered securities can transfer the rights on the securities through the transfer of creditor's rights. (2) Bearer securities refer to treasury bills, bearer shares and other securities without the name of the creditor. The rights of bearer securities are enjoyed by the holders and can be freely transferred, and the securities obligor is only responsible for the securities holders. (3) Indicative securities refer to securities in which the name of the first obligee is marked, such as indicative checks. It shows that the securities holder is the person designated in the securities, and the securities obligor only performs his obligations to the holder recorded in the securities. If the transfer of securities is instructed, the creditor must endorse and designate the next creditor, and the securities debtor shall perform it to the designated creditor. In modern economic society, property rights and securities are inseparable and integrated, and rights are securitized. Although the holder of securities does not actually possess the property, he can legally own the ownership or creditor's rights of the property by holding the securities. (2) Profitability refers to a certain income from holding securities, which is the return of investors' transfer of the right to use funds. Securities represent the ownership or creditor's rights of a certain amount of assets, and assets are a special kind of value, which will continue to increase in value in social and economic operation and eventually form a value higher than the original input value. Because the ownership or creditor's rights of such assets belong to securities investors, investors have the right to obtain the value-added income of these assets at the same time, so the securities themselves are profitable. The income of securities is represented by interest income, dividend income and the price difference between buying and selling securities. The amount of income usually depends on the appreciation of assets and the supply and demand of the securities market. (3) Liquidity of securities, also known as liquidity, means that securities holders can flexibly transfer securities according to their own needs in exchange for cash. Liquidity is the vitality of securities. The maturity of securities limits investors' flexible preferences, but its liquidity meets investors' random demand for funds in a flexible way. The circulation of securities is realized by acceptance, discount and transaction. The strength of securities liquidity is restricted by many factors, such as the duration of securities, interest rate level and interest-bearing method, credit, popularity, market convenience and so on. (4) The risk of risky securities refers to the possibility that the securities holder will not realize the expected investment income or even the loss of principal. This is caused by the maturity of securities and the uncertainty of future economic situation. Under the existing social production conditions, some investors can predict the future economic development and changes, and some investors can't predict them. Therefore, it is difficult for investors to determine whether and how much income they can get from the securities they hold in the future, which makes holding securities risky. (5) Term bonds generally have a clear repayment period to meet the needs of different investors and fundraisers for financing period and related rate of return. The term of the bond is legally binding, protecting the financing rights of both parties. Stocks have no term and can be regarded as indefinite securities. Legal characteristics of securities (1) Securities and property rights recorded in securities are inseparable. Securities must be made into securities by the payer in accordance with legal procedures and delivered to the holder, who must present and deliver the securities when exercising the rights contained in the securities. When negotiable securities are transferred, the rights contained in the securities are transferred to the transferee with the delivery. To enjoy the property rights represented by securities, it is necessary to hold securities. Once the obligee loses the securities, he can't exercise his rights to the securities. (two) the debtor of the securities is specific, that is, the holder of the securities can only request the debtor recorded in the securities to realize the creditor's rights. However, the creditors of securities can be changed due to the transfer of securities, and the legal replacement of holders of securities cannot affect the debtor's performance of debts. (3) The payment of the securities debtor is a unilateral debt, and the debtor may not ask the creditor to pay the corresponding consideration. Once the debtor has fulfilled the rights and obligations stipulated in the securities, he can recover the securities and eliminate the relationship between creditor's rights and debts. [1] The particularity of securities is as follows: (1) Securities are inseparable from the rights recorded in securities. (2) Securities holders can only claim rights from specific obligors. (3) The obligor for payment of negotiable securities has a unilateral obligation to pay at sight. Types of securities: classified according to the nature of rights represented by securities: (1) securities representing a certain currency (promissory notes, bills of exchange, checks) (2) securities representing a certain commodity (warehouse receipts, bills of lading) (3) securities representing a certain share (stocks) (4) securities representing a certain bond (bonds) from securities. (2) Marking the securities. (3) bearer securities. V. Practical Significance of Securities The emergence of securities can accelerate the concentration of capital, thus meeting the needs of expanding the scale of commodity production and commodity exchange. Portfolio is a form of virtual capital, which has no value in itself, but because it can bring some income to the holders, it can be bought and sold in the securities market at a price. The price of securities depends on the expected return of securities and the interest rate of bank deposits, which is directly proportional to the former and inversely proportional to the latter. In addition, changes in the relationship between supply and demand of securities, political stability, policy changes, national financial situation and the tension of market currency will all cause price fluctuations of securities.