The gold probably just got misplaced, because the US government wouldn’t steal another nation’s gold. From Eric Zuesse at strategic-culture.org:
The Syrian National News Agency headlined on February 26th, “Gold deal between United States and Daesh” (Daesh is ISIS) and reported that,
Information from local sources said that US army helicopters have already transported the gold bullions under cover of darkness on Sunday [February 24th], before transporting them to the United States.
The sources said that tens of tons that Daesh had been keeping in their last hotbed in al-Baghouz area in Deir Ezzor countryside have been handed to the Americans, adding up to other tons of gold that Americans have found in other hideouts for Daesh, making the total amount of gold taken by the Americans to the US around 50 tons, leaving only scraps for the SDF [Kurdish] militias that serve them [the US operation].
Recently, sources said that the area where Daesh leaders and members have barricaded themselves in, contains around 40 tons of gold and tens of millions of dollars.
Allegedly, “US occupation forces in the Syrian al-Jazeera area made a deal with Daesh terrorists, by which Washington gets tens of tons of gold that the terror organization had stolen, in exchange for providing safe passage for the terrorists and their leaders from the areas in Deir Ezzor where they are located.”
ISIS was financing its operations largely by the theft of oil from the oil wells in the Deir Ezzor area, Syria’s oil-producing region, and they transported and sold this stolen oil via their allied forces, through Turkey, which was one of those US allies trying to overthrow Syria’s secular Government and install a Sunni fundamentalist regime that would be ruled from Riyadh (i.e., controlled by the Saud family). This gold is the property of the Syrian Government, which owns all that oil and the oil wells, which ISIS had captured (stolen), and then sold. Thus, this gold is from sale of that stolen black-market oil, which was Syria’s property.