OnePay, a financial technology firm owned by retail giant Walmart, is reportedly adding Bitcoin and Ethereum trading to its mobile app, sources familiar with the matter told CNBC.  The firm is said to be working with stablecoin and crypto infrastructure startup Zerohash to implement custodying and trading solutions into its mobile banking application later this year.  “The move means that crypto is increasingly seen as a core offering that exists alongside traditional banking services like savings account ...