sell their notes directly to investors. Because of illiquidity of the secondary market and securities regulations, the market remained relatively quiet until 1980s. Then, in 1981, investment banks stepped in by providing assistance in the process of issuance and liquidity to the market and one year later, the SEC adopted its rule 415, which permitted delayed or continuous issuance of so-called shelf registered corporate securities, enabling issuers to register securities that may be sold for two years after the effective date of the registration without the need for approval for each individual offering. Because of these changes, investors also become more aware of this instruments and were willing to add it to their portfolios. This improved liquidity and helped the growth of the MTM market. In the beginnings, most of the issues were fixed rate, noncallable and unsecured debt of maturity shorter than 5 years. Throughout the years, due to specific needs of investors and businesses, more flexible forms, like notes with options or floating rates were invented. This also helped spread of its use to Euro markets. References External links Medium Term Note – MTN, Investopedia Anatomy of the MTN market, The Free Library Interest-bearing instruments