The dollar index slipped during Wednesday's session, while a sharp rally in the Japanese yen captured market attention and the Canadian dollar strengthened following the Bank of Canada's decision to hold interest rates steady.

The Bloomberg Dollar Spot Index retreated 0.2% to 1196.30. The USD/JPY pair dropped 0.8% to 158.87, as the yen's rapid appreciation against the greenback put traders on high alert for potential official action to support the Japanese currency.

Meanwhile, USD/CAD fell 0.4% to 1.3842. The loonie gained ground alongside rising Canadian government bond yields, as market participants increased their bets on a rate hike later this year in response to the central bank's hawkish tone.

In other currency moves, the New Zealand dollar weakened 0.8% to 0.5847, marking its lowest level in about a month. This came after the Reserve Bank of New Zealand raised its key interest rate for a second consecutive meeting, signaling a shift toward a less stimulative policy stance aimed at curbing inflationary pressures.

The Australian dollar, however, bucked the trend, advancing 0.3% to 0.7169. Australia's economy unexpectedly accelerated in the second quarter, reinforcing the case for another rate increase by the Reserve Bank of Australia as inflation remains elevated.

Elsewhere, the euro slipped 0.1% to 1.1586 against the dollar.