Dollar Bulldozes Its Way Through Asian FX With Help From Yuan

• Greenback got a boost Tuesday as China loosened grip on yuan
• MSCI EM currency index falls to lowest level this year

The resurgent dollar cut a swath through global emerging-market currencies Tuesday, weakening many through closely watched levels that forced some officials to step in to stem the losses.

China’s move to weaken its daily reference rate for the yuan added to the selling pressure, with the Indonesian rupiah, Indian rupee and the South Korean won among the hardest hit. But the dollar impact was broader, with a global gauge of emerging-market currencies falling to fresh lows for the year. Stocks also extended their losses, with a benchmark of emerging-market equities erasing their gains for the year.