A capital flow is a transaction that changes financial claims between residents of an economy and nonresidents. In macro analysis, separating inward from outward investment helps identify whether a net financing change came from foreign investors or residents' own decisions. The boundary is economic residence, not citizenship: residence follows the unit's predominant economic connection to a territory. IMF BPM6, paragraphs 4.113–4.117.
These transactions appear in the financial account of the balance of payments. The statistical capital account instead records capital transfers and transactions in non-produced, nonfinancial assets. The everyday phrase “capital flows” therefore covers much more than that account. ECB's account definitions.
Two sides, then a net balance
For an asset–liability presentation, define the sides as follows. IMF BPM6, paragraphs 8.1–8.9.
| Side | Transaction measure | Positive value means |
|---|---|---|
| Outward | Residents' net acquisition of external financial assets | Residents acquire more external assets than they dispose of. |
| Inward | Residents' net incurrence of liabilities to nonresidents | External liabilities increase through transactions. |
In capital-flow research these separate sides are often called gross outflows and gross inflows. “Gross” here means the asset and liability sides have not been offset against each other. Each side already nets increases against decreases: asset purchases against disposals, or liability incurrence against reductions. It does not mean all purchases before sales. Either side can be negative. Koepke and Paetzold, IMF Working Paper 20/171, section II.B.
Consider a fictional economy in one quarter, with transactions in millions of one reporting currency, at current transaction values, without seasonal adjustment or annualisation. Residents acquire foreign financial assets of 40, while nonresidents acquire additional claims on residents of 25. Assume no offsetting asset disposals or liability reductions in this example. Thus the gross outward side is 40, the gross inward side is 25, and
The economy can have substantial inward investment while still being a net outward investor.
Original fictional example. Separate asset and liability transaction flows are 40 outward and 25 inward; offsetting the sides gives 15 net outward.
Keep the sign definition beside the series. The financial-account balance, defined as net asset acquisition minus net liability incurrence, is +15 here. A series defined as net capital inflow subtracts assets from liabilities and reports . These describe the same transactions. IMF BPM6, financial-account presentation.
A flow is not a change in portfolio value
The international investment position (IIP) records external assets and liabilities at a date. Its change also includes exchange-rate and market-price revaluations and other changes, such as write-offs or reclassifications. An existing foreign shareholding can rise in domestic-currency value without any new investment transaction. Differencing IIP stocks alone therefore does not recover capital flows. ECB's stock–flow reconciliation.
For a trading signal, check the component and coverage: direct investment, portfolio investment, bank-related flows and official reserves are not interchangeable. Fund subscriptions are also a different observation from cross-border security transactions. Preserve the release vintage available at the decision date, alongside the units, period, adjustment basis and sign. IMF capital-flow data guide.
Check the methodology edition as well. The ECB's July 2025 e-book describes BPM6-based compilation; the IMF has released BPM7 and separate implementation guidance. A new manual's release does not establish that every historical or current series has adopted it. IMF standards update.
Read a negative inward flow
In another fictional quarter, residents buy external assets for 18 and dispose of external assets for 8. Nonresidents buy domestic securities from residents for 12 and sell domestic securities to residents for 15. These are the only financial-account transactions; all amounts are millions of the same reporting currency. What are the two sides and the net outward flow?
Answer. Net asset acquisition is . Net liability incurrence is : nonresidents reduce their claims on residents. Net outward flow is , and net inflow is −13. Treating inward flow as positive 3 would reverse the meaning of the nonresident sales.
Sources
- IMF: Balance of Payments and International Investment Position Manual, sixth edition — residence, paragraphs 4.113–4.117; financial account, paragraphs 8.1–8.9.
- ECB: EU Balance of Payments and International Investment Position statistical sources and methods, July 2025 — general principles, recording and reconciliation.
- Robin Koepke and Simon Paetzold: Capital Flow Data — A Guide for Empirical Analysis and Real-Time Tracking, IMF Working Paper 20/171, 2020 — sections II.A–II.B.
- IMF: BPM6 update page — BPM7 release and implementation materials.