Nikkei Currency Index, the trade-weighted exchange rate index according to value of exports and imports of each country, indicates overall value of each currency. For example, if the yen rises against the U.S. dollar, it may not rise against the euro. Yen index of Nikkei Currency Index indicates overall value of yen against other countries.
At present, 25 currencies are calculated daily as a value of 2015 is 100. The reference year is periodically reviewed. As for the Japanese yen, the U.S. dollar, and the euro, indices appear in morning edition of The Nikkei.