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Not sure what numbers were used for the 2.6 billion
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Simple conversion from a previous poster's formula: 1 trillion diff @ 42K USD/BTC -> x diff @ 110 USD/BTC
x diff = 1 trillion diff * 110 / 42000 ≃ 2.6 Billion diff.
Factoring in the miner's price is a bit tricky as you don't know when it was bought, how much electricity it consumed over time, what the sale price was (+ other associated costs) so it's more like an upper limit that probably won't be reached (never say never though...), unless you disregard the payback time (and then we're back to uselessness).