The domestic currency continued to sink at the forex market on Wednesday. The rupee sunk to an all-time low of 72.91 against the US dollar after opening at 72.87 earlier in the day. The domestic currency was quoting 22 paise lower at a fresh record low of 72.91 against the US dollar in morning trade amid surging crude oil prices and uanabated foreign fund outflows, reported news agency Press Trust of India (PTI). Escalating trade war concerns, consistent dollar demand from banks and importers, mainly oil refiners, following higher crude oil prices, kept the rupee under pressure, dealers were quoted as saying in the PTI report.