The limitations of stock exchange are as follows:
(i) Lack of uniformity and control of stock exchanges.
(ii) Absence of restriction on the membership of stock exchanges.
(iii) Failure to control unhealthy speculation
(iv) Allowing more than one stock exchange in the place.
 

Bull :
(a) A Bull or Tejiwala is an operator who expects a rise in prices of securities in the future.
(b) In anticipation of price rise he makes purchases of shares at present and other securities with the intention to sell at higher prices in future.
(c) He is called bull because just like a bull tends to throw his victim up in the air, the bull stimulates the price to rise. He is an optimistic speculator.
Bear :
(a) A Bear or Mandiwala speculator expects prices to fall in future and sells securities at present with a view to purchase them at lower prices in future.
(b) A bear does not have securities at present but sells them at higher prices in anticipation that he will supply them by purchasing at lower prices in future. A bear is a pessimistic speculator.

(i) Stag:
(a)  A Stag is cautious speculator in the stock exchange.
(b) He applies for shares in new companies and expects to sell them at a premium, if he gets and allotment.
(c) He selects those companies whose shares are in more demand and are likely to carry a premium.
(d) He sells the shares before being called to pay the allotment money. He is called a premium hunter.
(ii) Lame duck:
(a) When a bear finds it difficult to fulfill his commitment, he is said to be struggling like a lame duck.
(b) A bear speculator contracts to sell securities at a later date. 
(c) Moreover, the buyer is not willing to carry over the transactions.

National stock market system was advocated by the Higher powered group on the establishment of New stock Exchanges headed by Shri. M.J. Pherwani (popularly known as pherwani committee).
At present the National stock Market in India comprises the following:
(i) National Stock Exchanges of India Limited (NSE)
(ii) Stock Holding Corporation of India Limited (SHCIL)
(iii) National clearing and Depository System (NCDS)
(iv) Securities Trading Corporation of India. (STCI)

(i) NSE was incorporated in November, 1992.
(ii) It is a countrywide, screen based, Online and order driven trading system.
(iii) It uses satellite link to spread trading throughout the country thereby connecting members scattered all over the India.
(iv) Through computer network, member's orders for buying and selling within prescribed prices are matched by central computer with each other and instantly communicate to the trading member.
(v) NSE has two segments, i.e. Debt segment and capital segment. It has ushered in transparent, screen based and user friendly trading of global standards.