Question: I'm looking for a good job and I came to know about vacancies in company dealing in capital market. Will my income be halal if I work in that company?

Answer: 
As far as i know, according to the view of Shia, it won't be Haram if there is not any negative or haram ponit in the different jobs. Hence apparently the mentioned job is not Haram.
(of course if u r sure that the essence of the mentioned occupation is not haram either.
Any company that is interest-based or deals with taking and giving interest, it is not allowed to work for that company. Even writing down or typing the interest transaction in computer is haram. Because the prophet has cursed the taker of interest, the giver of interest, and the man involved in writing down the interest transactions.