What is the disadvantage of having a single stock?

if the company goes bankrupt

or if the whole stock as a whole crashes

then you would lose all your money or alot of it

but if the single company is good

in time you will get your money bank

as long as the company didnt go bankrupt

1 stock company is very good

if its a good company

because

its easy to manage it

and learn about the ups and downs of it