Refers to a huge portfolio that relies on multiple securities to offset the unsystematic risks of each security. That is, the natural adjustment of cash flow according to currency changes. This is a continuous precaution against the risk of exchange rate fluctuations. If the increase or decrease of local currency cash flow just offset the devaluation or appreciation of the currency safely, then the expected exchange rate of US dollar cash flow will remain unchanged. However, this perfect natural hedging is rare. Companies can achieve natural hedging through management, financial or money market hedging.