And speculation, as it says in the headline of that NYT article. The volume of bitcoins bought with bolivars (Venezuela's currency) is inherently limited: you

And speculation, as it says in the headline of that NYT article. The volume of bitcoins bought with bolivars (Venezuela's currency) is inherently limited: you would only want to sell bitcoins in exchange for bolivars if you could spend the bolivars immediately. That basically limits the sellers to people already having bitcoin and living in Bolivia.