The requirements of an Investor Visa differ from country to country. Hence the documents needed will also depend on the country that you are applying for.
The documents required also depend on the Visa category that you apply for.
For example, the document checklist for the UK Innovator Visa is different from the Sole Representative Visa of the UK. For the newly announced Start-Up Visa of the UK, you need an “endorsement letter” from an authorized entity in the UK. Such an endorsement letter is not needed for Innovator Visa or the Sole Representative Visa.
Similarly, the document checklist for the various Investor Visas in different provinces of Canada is different.
It is highly recommended to consult an Immigration Expert while applying for an Investor Visa to get the right guidance. Not only will the Expert be able to explain to you the whole process but also guide you on all the supporting documents required.