How do securities markets help firms raise funding and enable investors to trade?

"16.6 Securities Markets 6. How do securities markets help firms raise funding, and what securities trade in the capital markets? Securities markets allow stocks, bonds, and other securities to be bought and sold quickly and at a fair price. New issues are sold in the primary market. After that, securities are traded in the secondary market. Investment bankers specialize in issuing and selling new security issues. Stockbrokers are licensed professionals who buy and sell securities on behalf of their clients. In addition to corporate securities, investors can trade U.S. government Treasury securities and municipal bonds, mutual funds, futures, and options. Mutual funds are managed by financial-service companies that pool the funds of many investors to buy a diversified portfolio of securities. Investors choose mutual funds"