It isn't so much take over Bitcoin..

Bitcoin = 7 billion+
Ethereum = 1 billion+

So about 1/7th of the way of beating Bitcoin in value - and maybe compete on the side as a currency though the devs always stress this isn't the purpose of Ethereum and would rather work with Bitcoin.

The fact Ethereum keeps touching 1 billion+ and beyond makes it worth paying attention to.

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By the way, the price of Bitcoin has already pretty much been adjusted for - so don't expect a HUGE increase but maybe a bounce up and down due to HYPE over the halving.