Am I looking at the same data as you? Siacoin is to my knowledge 11 x the market capitalization of MASS. Are you sure you correctly checked the data before responding to me? If that is the only difference I would rather store my stuff with Siacoin as it is the more secure network.
MASS achieved all this in less then a year, while Siacoin is there for around 5 to 6 years. Give this much time to MASS and then compare market cap of both coins.