Investors are snapping up gold, pushing the commodity above $4,000 a troy ounce for the first time. WSJ’s David Uberti uses three charts to help explain what’s behind the rush and what could come next. Chapters: 0:00 Gold prices are skyrocketing 0:20 Price of gold 1:55 Central banks 2:42 Dismal dollar 3:29 What’s next? News Explainers Some days the high-speed news cycle can bring more questions than answers. WSJ’s news explainers break down the day's biggest stories into bite-size pieces to