A giant of Canadian retail grew his net worth 10% in a matter of weeks, while an energy baron sank below the billion-dollar mark

This is one in a series of periodic updates we’ll provide on the members of our ranking of Canada’s Richest People. We’re tracking how their net worth changes throughout the year and will highlight some notable shifts like these.

▲ Alain Bouchard

Net worth as of Oct. 30, 2015: $3.9 billion

Net worth as of Dec. 7, 2015: $4.3 billion

Change: +10% ($369 million)

Alain Bouchard grew his net worth by 55% in the span of a year, but he’s continued to add to his wealth over the past month. Since the start of November Bouchard’s has grown his net worth by almost $370 million, which is equivalent to $9.7 million a day, thanks largely to gains of his significant holdings in convenience store and gas bar operator Alimentation Couche-Tard. The company has been on an aggressive acquisition spree for the past several years and that trend continued in early December when Couche-Tard inked a deal Topaz and its network of 464 gas stations in Ireland for an undisclosed price.

▼ Clay Riddell

Net worth as of Oct. 30, 2015: $1.3 billion

Net worth as of Dec. 7, 2015: $909 million

Change: -31% (-$405 million)

Clay Riddell is no longer a billionaire. The Canadian oil tycoon’s net worth has dropped by 30% in a little over a month. That slide, which translates in to roughly $405 million, is on top of the 65% drop in Riddell’s wealth from a year ago. Riddell’s holdings, which are heavily concentrated in Alberta’s oil patch, have been hit particularly hard, but none as much as Paramount Resources. Since the beginning of November shares of the once mighty oil and gas company has lost more than half their value. Paramount’s market cap is dropped to $624 million, which is the first time since 2008 it’s fallen below the $1 billion threshold.