The point where we diverge I think is that it can be alot less risky to own one company vs. the whole market.
As a theoretical example: suppose a listed company only has cash worth 100 B$, and is listed for 40$B. It has nothing else (no employees, production, ..).
Buying that company, delisting it and getting the cash out has virtually zero risk.
In the past the rough equivalent of that scenario (e.g. extremely undervalued real estate hidden in the balance sheet) has existed.
How would diversification help you here? It's not stupid to put all your money in one place if that place is safer and offers higher returns than all the alternatives.
Since few opportunities are so clear cut it does make sense to diversify usually though. It is a margin of safety one can build in if required.
The question then is whether one believes you can narrow down the certainty of value enough to not need the diversification route in practice.
Some people think they can, others don't and everything in between. Extreme at the one end means indexing only, extreme at the other end means concentrating in one company.
Another example, a bit more practical: suppose I invest in two companies to diversify. And then these two companies merge. Has my risk profile changed? Should I sell half my holdings and find another company to diversify?
Diversification has its merits (I use it myself!), but it's just another tool, not always the best one for everyone in my book.
As a theoretical example: suppose a listed company only has cash worth 100 B$, and is listed for 40$B. It has nothing else (no employees, production, ..).
Buying that company, delisting it and getting the cash out has virtually zero risk.
In the past the rough equivalent of that scenario (e.g. extremely undervalued real estate hidden in the balance sheet) has existed.
How would diversification help you here? It's not stupid to put all your money in one place if that place is safer and offers higher returns than all the alternatives.
Since few opportunities are so clear cut it does make sense to diversify usually though. It is a margin of safety one can build in if required.
The question then is whether one believes you can narrow down the certainty of value enough to not need the diversification route in practice.
Some people think they can, others don't and everything in between. Extreme at the one end means indexing only, extreme at the other end means concentrating in one company.
Another example, a bit more practical: suppose I invest in two companies to diversify. And then these two companies merge. Has my risk profile changed? Should I sell half my holdings and find another company to diversify?
Diversification has its merits (I use it myself!), but it's just another tool, not always the best one for everyone in my book.