Foreign direct investment is the provision of capital into a company or project by a financier who is from a foreign country. In portfolio investment, anyone can invest in the portfolio, whether or not he is from a local company or a foreign company.

Portfolio investment refers to investments in foreign countries that are withdrawable at short notice, such as investment in foreign stocks and bonds.

Itay Goldstein has written:

'Foreign direct investment vs. foreign portfolio investment' -- subject(s): Foreign Investments, Mathematical models, Portfolio management

Debt flows, Foreign Direct Investment Flows and Portfolio Investment Flows

An investment portfolio is a group of investments in which an investor intends to make a profit on the original invested money. A savings 529 plan would not be included in a investment portfolio as it is an education savings plan not an investment plan.