Why do we add a new security to our portfolio ?
To reduce risk and ensure not all our eggs are in same basket, the underlying thought process is if stock A doesn’t do well at least stock B will provide some returns and compensate for loss if any in stock A
This makes perfect sense if you go by what Harry M. Morkowitz said in 1950’s [emphasis mine]

The investments have different types of risk characteristics, some caused systematic and market related risks and the other called unsystematic or company related risks. Markowitz diversification involves a proper number of securities, not too few or not too many which have no correlation or negative correlation. The proper choice of companies, securities, or assets whose return are not correlated and whose risks are mutually offsetting to reduce the overall risk

It explains why investors invest in diverse spectrum of industries whose fortunes are not tied to each other
However many investors feel discomfort in adding a new company from a similar industry, At least I do. My thinking process is I already own TCS what the use of adding another IT company in the portfolio ? After all the company related … Read the rest