The shape of the trend of a country’s trade balance following a devaluation. A lower exchange rate initially means cheaper exports and more expensive imports, making the current account worse (a bigger deficit or smaller surplus). After a while, though, the volume of exports will start to rise because of their lower price to foreign buyers, and domestic consumers will buy fewer of the costlier imports. Eventually, the trade balance will improve on what it was before the devaluation. If there is a currency appreciation there may be an inverted J-curve.