SENSEX is a index consists of 30 companies, if any movement happens in these listed shares ,SENSEX will move up or down
the thirty companies are
Scrip Code Company 500325 RELIANCE
500209 INFOSYS TECH
532174 ICICI BANK L
500510 LARSEN & TOU
500010 HOUSING DEVE
500875 I T C LTD
500112 STATE BANK O
500180 HDFC BANK LT
532540 TCS LTD.
500312 ONG CORP LTD
532454 BHARTI ARTL
500103 BHEL
500570 TATA MOTORS
500470 TATA STL
500520 MAHINDRA & M
500696 HIND UNI LT
532555 NTPC LTD
532286 JINDAL STEEL
500440 HINDALCO IN
500900 STERLITE IN
500400 TATA POWER
532500 MARUTISUZUK
507685 WIPRO LTD.
500087 CIPLA LTD.
500182 HEROHONDA M
500390 REL INFRA
532868 DLF LIMITED
532532 JAIPRAK ASSO
532712 REL COM LTD
500410 ACC LTD
Apart from this there are so many causes for the movement
1)Fiancial results announced by the companies(THIS 30) 2)Financial decisions taken by the CENTRAL GOVT and it's impact on the 30 companies 3)Foreign Intitutional Investor's investment (FII'S) 4)Take an example ACC ,,,cement company...if the real estate bomms up automaticaly the cement turnover moves up