Same happened to me. Tried to buy some Molten Slivers while they were low in price and when I clicked “Buy”, the items didn’t show as being bought. The “Buy” button also didn’t grey out, so I figured it was a misclick. Clicked the “Buy” button again to no avail, thinking maybe I needed to get back to Lion’s Arch to make it work, for whatever reason suddenly.
Got to Lion’s Arch and it seems that the entire map of people were going berserk due to their gold being lost. I looked in my bag to find out that my original 86 Silver had gone down to just 12 Silver. Seems everyone is losing major money right now. Would definitely hope that the losses will be compensated for everyone.