Spot gold smashed through $4,000 an ounce for the first time, as concerns over the US economy and a government shutdown added fresh momentum to a scorching rally. Gold has jumped more than 50% this year in the face of uncertainties over global trade, the Federal Reserve’s independence and US fiscal stability. Security services group Verisure’s shares rallied in its trading debut, after the initial public offering raised about €3.2 billion ($3.72 billion) in the largest European debut in three