Opposition leader Juan Guaidó, whom the U.S. considers Venezuela’s legitimate president, during a rally last month. Creditors from hedge funds to oil companies are moving closer to seizing billions of dollars in Venezuela’s overseas assets, posing a threat to an opposition movement that has sought to protect the assets for an eventual change of government. Tens of billions in Venezuelan money and property is up for grabs, including Houston-based oil-refining company Citgo Petroleum Corp., gold bullion housed in the Bank of England, bank accounts in New York and real estate and aircraft in South Florida, according to Venezuelan opposition…