Foreign Exchange Market Intervention

Foreign-exchange market intervention occurs when a central bank buys or sells foreign currency to influence exchange-market conditions. To support a depreciating domestic currency, it typically sells foreign currency and buys domestic currency, countering the imbalance between demand and supply that is weakening the exchange rate.

How foreign-currency sales support the exchange rate

Depreciation means that more domestic currency is needed to buy a unit of foreign currency. For example, when demand for dollars exceeds their available supply at the prevailing exchange rate, the rupee faces downward pressure.

• The central bank sells dollars from its foreign-exchange reserves, increasing the supply of dollars available to the market.
• Buyers pay domestic currency for these dollars, so the transaction simultaneously creates demand for domestic currency.
• These transactions can slow depreciation or support an appreciation relative to what would otherwise have occurred; they do not guarantee a particular exchange rate.
• Intervention can also influence market expectations by signalling the central bank's willingness to counter disorderly conditions, although its effectiveness depends on credibility and underlying pressures.

Domestic liquidity and sterilisation

Foreign-exchange intervention also affects the domestic monetary system. When the central bank receives domestic currency in exchange for foreign currency, it absorbs liquidity from the banking system.

• If this liquidity contraction is not offset, it can put upward pressure on short-term interest rates, potentially providing additional support to the currency while tightening domestic financial conditions.
• Through sterilisation, the central bank offsets the domestic liquidity effect of its foreign-exchange transaction.
• After selling foreign currency, it can inject liquidity, for example by purchasing government securities, to prevent an unintended monetary tightening.

Purpose and limits in the Indian context

India has a market-determined exchange rate. The Reserve Bank of India intervenes to contain excessive volatility and maintain orderly market conditions, rather than defend a fixed exchange-rate level.

• Sustained foreign-currency sales draw down reserve buffers, limiting how long intervention can counter persistent selling pressure.
• Intervention can smooth temporary demand-supply imbalances, but it cannot indefinitely offset pressures arising from weak economic fundamentals or sustained capital outflows.
• Durable currency stability requires credible macroeconomic policies; intervention complements, rather than substitutes for, measures addressing inflation and external imbalances.