This is what a 29-minute stock market crash looks like.

Basically it’s the Chartbeat of my nightmares. 

China had to close trading on its markets today following a steep dive that has been attributed to a variety of possible maladies, including concerns about slowing growth in the world’s second-largest economy, a weak yuan, and general confusion about how the Chinese government is trying to manage market turmoil.

In 2015, the government spent hundreds of billions of dollars propping up the stock market after a series of abrupt drops, which were themselves partly precipitated by investor concerns that the government had created a bubble in the stock market.