There is no investment program in Portugal leading to obtaining citizenship. But you can get a residence permit by investment according to Portugal Golden Visa program.
Investors can choose one of seven options:
Buy a property for restoration for €350,000 or a new real estate for €500,000.
Purchase of investment fund units for €500,000.
Supporting arts and restoring cultural heritage for €250,000.
Investments in research activities for €500,000.
Capital transfer of €1,500,000.
Business investments from €500,000.
Opening a company with the creation of 10 job positions.
In five years, residence permit holders can apply for Portuguese citizenship.