What goes up, must come down.

That was the theme during a wild day of trading in Canada’s marijuana industry.

First, a meteoric rise early Wednesday led to a brief trading halt in several marijuana stocks after huge spikes tripped a circuit breaker.

Single-stock circuit breakers are used to help control short-term volatility and can be triggered when there’s a sudden, dramatic shift in a stock.

Along with Canopy, Aphria Inc., Mettrum Health Corp., Organigram Holdings Inc., Supreme Pharmaceuticals Inc., and Aurora Cannabis Inc. were also affected.

Normal trading resumed for each stock after respective five-minute halts.

But later Wednesday stocks were halted again after a rapid sell off.

The Investment Industry Regulatory Organization of Canada (IIROC) says it “can make a decision to impose a temporary suspension (halt) of trading in a security of a publicly-listed company. Trading halts are implemented to ensure a fair and orderly market.”

Looming legalization in Canada, as well as legalization for medicinal and recreational purposes in several U.S. states is driving stock prices in the emerging industry.