Comdoll is short for the term “commodity dollars”.
Currencies like the Australian, Canadian, and New Zealand dollars are usually called comdolls because their respective economies are highly dependent on exporting commodities. Australia, for one, is the second largest gold producer in the world, behind only China (2015), while Canada is the fifth largest of the world’s oil producers (as of 12/2014).
Investors often need to get their hands on comdolls if they want to trade commodities. This is why the comdolls’ price action is usually correlated with commodity prices.