Avoid Mistakes to be a Successful Investors :

Eg. Mr. A had invested

$ 100 in Yahoo share in 2000...

Today in 2016

( after 16 years ) @ $ 4.8.

Negative CAGR return 17.28%

Another Eg. Mr. A invested

$ 100 in Google in 2000...

Today in 2016 Value $ 12000

Postitive CAGR 34.88%

Conclusion :
Diversification in SAME assets class will help u to avoid capital losses

and achieve consistent positive good return in long term.

And Mutual Funds dose the same.

So always invest in a portfolio not in a company to avoid loss.