Shares of cruise-line operators sailed to big gains on Wednesday as investors placed a bet that improving relations between the U.S. and Cuba could lead to new opportunities for tourism. Shares of Carnival, Norwegian Cruise Line and Royal Caribbean all rose in early trading Wednesday, outpacing the Dow Jones Industrial Average, after the Obama administration said it plans to lift many of its existing travel restrictions on Cuba. The new regulations will make it easier for Americans to visit to Cuba under the 12 categories of travel that are currently allowed, The Wall Street Journal reported, though it isn’t immediately clear if or when the island will be open for mass tourism.