In a sense, an index fund is diversified because the portfolio of securities it represents consists of numerous stocks or bonds. (ally.com)
For those of you that might think that this theory is brand new, it has actually been around for decades and studied by numerous stock market theorists. (thecollegeinvestor.com)
The concentrated investors outperformed the people with numerous stocks by more than two percentage points a year. (canadianbusiness.com)