You appear to be using WinRunner, by your other question here. WR is quite adequate to test ant type of GUI with the exception of .NET specific. It can test 90% of .NET but not all of it. As for performance, there are many tools on the market and also available as freeware which can do the job for you.
Dinesh, there are too many undefined variables associated with this context to supply a meaningful answer.
Are you looking for a single tool for both functional and performance testing?
what is the technology this is built on?
what is the budget?
what is the test strategy?
will there be a high level of automated script reuse?
What is specific about the share market domain that makes it worth stating - is there a specific share market (exchange) and trading platform you are interacting with?
The above is a minimal subset of questions that require answers prior to the ability of this forum to supply a potentially meaningful answer...
It would be very difficult to answer your questions just suggest a tool or tools for you. I think you should evaluate those tools on the market upon your project testing requirements. So how to do the evaluation would be more useful for you. You could find a lot related information from the FAQ.
Kishore, why do you say Silk is better? Winrunner, IBM Functional Tester and Quick Test all support Java. What features of Silk do you think makes it more appropriate for Financial applications than the other tools?
I'm with cblue, Kishore. Why silk? Why not QARun or TestPartner as well?
And Rich, I am not sure how you drew the inference from the initial post that he is using WR. Not taking you up on it - I'm just wondering what I missed that you saw.
Neill nailed it - there are way too many undefined variables to even suggest a tool, let alone the best tool. We don't even know if this is running on a client-server network or on a mainframe. That will make a huge difference in available tools.