Said another way, DXJ has outperformed the ProShares UltraShort Yen (NYSE: YCS ), a double-leveraged play on the yen against the dollar. The Nikkei 225, Japan's benchmark equity index, has surged almost nine percent in the past month as investors have bought into the notion that newly elected Prime Minister Shinzo Abe could actually prove successful in weakening the yen. The headlines are a welcome respite from nearly two decades of spiraling equity prices, deflation, rising deficits and assorted other black marks that have plagued Japan, the world's third-largest economy.