Boeing signaled Tuesday that it could raise up to $25 billion in new stock or debt to shore up its balance sheet after years of heavy losses. The company said in back-to-back regulatory filings that it could raise the cash over the next three years and enter into a new borrowing agreement with lenders. Boeing has lost more than $25 billion since the start of 2019, and its finances are under new pressure as a strike by workers who build most of its airline jets factory goes...