Investing into indices is straight forward but not preferred approach for me.
Pros:
Cons:
Typically indices deliver averages results. However There are 2 ways to get an over average result:
Ability to time market, according to the most successful investors, is an illusion. Thus must not be taken seriously.
Investing into smallcaps to beat DJIA and SP500 however can be a vital idea.
Since I aim to get results better than averages, indices is not a preferred investment. However in some cases it can be justified:
After significant market drop (at least 30%).
P/E or Shiller P/E is recommended to be not higher than 15.
Small cap:
Mid cap:
Large cap:
Indices like DJIA and DAX must be avoided for being less profitable and at the same time not that well diversified.
After opening initial position some cash must be left to ensure I'll be able to average down if necessary.