Actually, we are doing clustering, but as you found out it's not perfect. Like you said, we don't want the same news repeated over and over again to be factored in the bullbear index.
I like this idea: Instead of showing 10 most recent articles it's better to show N-most recent articles with S-most recent trend.
I like this idea: Instead of showing 10 most recent articles it's better to show N-most recent articles with S-most recent trend.
I'll look into it.