The US has bought up yen to strengthen the currency for the first time in almost 30 years, with the moves raising questions about America’s motivesThe US has launched a bid to prop up the value of the yen, marking an extraordinary coordinated intervention with Japan’s government to halt the currency’s fall as it approaches 40-year lows.Japan has been struggling to stop an accelerating slide in the yen, which has been piling pressure on its already flailing economy. Washington's decision to join Japan in supporting the battered yen has prompted questions over what motivated the rare coordinated intervention. Key points and original sources are listed below.

• The US has bought up yen to strengthen the currency for the first time in almost 30 years, with the moves raising questions about America’s motivesThe US has launched a bid to prop up the value of the yen, marking an extraordinary coordinated intervention with...S1

• Washington's decision to join Japan in supporting the battered yen has prompted questions over what motivated the rare coordinated intervention.S2