what financial assets can be bought in argentina with pesos and sold in the US?

obviously not gold and i'm guessing other such commodities as the government has banned their sale, but what about traditional financial derivatives, etc? how are those priced in light of the severely overvalued exchange rate?

reason I ask is there's a mushrooming demand for bitcoin as locals are desperate to avoid the severe inflation going on, so a US citizen could buy bitcoins using a us bank account, sell them locally for pesos at the informal exchange rate, and then if you could find an asset you could buy locally with pesos and then sell back in the states for dollars, have a pretty simple and easy arbitrage opportunity. The export tax they've been imposing makes things more difficult, but even with it there might be a large enough margin.