How does Net Foreign Assets (NFA) differ from Net Foreign Investment (NCO)? How does Net Foreign Assets (NFA) differ from Net Foreign Investment (NCO)? Yes, the former counts assets, and the latter counts investment, but I can't quite wrap my head around the difference.
One is a stock another is a flow.
Net Foreign Assets are:

Net foreign assets (NFA) determines whether a country is a creditor or debtor nation by measuring the difference in its external assets and liabilities. Net foreign assets (NFA) refer to the value of overseas assets owned by a nation, minus the value of its domestic assets that are owned by foreigners, adjusted for changes in valuation and exchange rates.

Net Foreign Investment is:

Foreign investment involves capital flows from one country to another, granting the foreign investors extensive ownership stakes in domestic companies and assets.