@Anuragrai
well first no sorry and the word sir,,,shyam will do,,well i couldnt not see ur question before,,i am surely gonna help u out,well first u need to learn a lot den only think of entering into markets.
reasons are many for that matter.
1.the biggest reason is the performance and reputation of the company and its history,their quarterly profits and margins,,business models etc.
2.then look for specific sectors like some time back IT was a craze ,,but not so now,,now oil and construction,,reality are doing well.Steel too.
3.There are also rumours in the market,,sent out by speculators then share prices of the company goes up...in short if the companies share is more in demand and is being purchased the price goes up.
4.any major news like selling stake ,,or acquistions and all can see share prices moving either way.
To be honest there are so many other factors,,but they are the major ones,,still if u have doubt ,,,i am here.