Quote from Cutten:
Characteristics of a business:
1) Customers
2) A product
3) Employees
4) Sales
5) Customer support
Sole-trading has none of the above. Thus, trading is not a business. Running a hedge fund, or a mutual fund - THAT is a business. But trading isn't.
Quote from mrman500:
1) I sell options to customers.
2) My product are options.
3) I have one employee - me and a subcontractor - my broker.
4) I make sales to people who give me money.
5) My product is perishable & requires no customer support - like the corner ice cream stand.
Manufacturing is not the only kind of business. Retailing is another.