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Come halving, his 20btc will also turned 40btc.
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It's quite a leap of faith that the price of BTC will double up after the halving. I am not saying you are wrong, but personally i find it unlikely that the price will double just because of the block reward going down.
well. if it don't double still, the point is that they gain.
to prove these investors are investing to wait for the progress of the platform. i doubt they'd not protest if say the team will only release 100K of thier waves everyday since june14th.