There could not be an S&P 500 stock index in Germany.

Simply because there are no listed companies.

Deutsche Börse currently has 441 companies in its Prime and General Standard segments.

Only a fraction of the approximately 3 million companies in Germany can be invested transparently and liquidly.

The thousands of global market leaders known as hidden champions, whom hardly anyone knows, do not have to publicly report in detail on their activities every quarter, as listed companies have to.

The transparency on the stock exchange is good.

However, most companies shy away from this.

From an investor's point of view, that's a pity, because investors are missing out on the immense return opportunities offered by start-ups and resourceful traditional companies.

It is therefore high time that regulators, banks and stock exchanges try to make companies off the stock market more investable, if at all, for investors.