By Ripple and Ethereum like I already wrote in my first post. Unwashed masses don't really care for the finer qualities of bitcoin such as being decentralized. They see more potential gains in the aforementioned cheaper alternatives. Now the rates of these coins are driven by the crazy stampede of these less informed "investors" and bitcoin is just not seen as a good investment (already high unit price - the train has gone, huge fees, slow operation, no smart contracts etc etc). For these people the low unit price of Ripple alone is enough to keep pumping it until it's bigger than BTC. It does not help either that bitcoin is continuously hit with the flak from it's opponents in governements, banking world etc. The alternatives are growing next to it with almost zero opposition.