Every day currency exchange rate always change. Usually, this happens because of market activity. If the market activity in a country is better then their currency exchange rate will increase. The opposite can happen if market activity is low, the currency exchange rate in there will weaken. Dollar US is benchmark scores for all currencies. You can see many prices from specific commodity used dollar US for their price as crude oil.
Crude oil prices use dollar US for their prices per barrel. The condition of dollar US can influence crude oil price. If dollar US weaken then crude oil prices can crash too. It caused several currencies are higher than dollar US. This condition can disserve many people like the players share in energy section. They stock value can crash and their loss. If you want to see about development of crude oil prices and want to start to buy shares in energy section, you can visit moneymorning.com/tag/oil-prices/.