There is no such thing as "over capitalization." Capitalism is an economic and political system whereby a country's trade and industry are not controlled by the state, but by private owners for profit. This promoted free enterprise and stimulates economic growth.
Are you referring to "unrestrained capitalism"? If so that's basically capitalism without regulations or safeguards. It can result in a small minority of super-rich corporations having to much power and control over world events, basically corporate feudalism.