The attacker sold 500,000 bitcoins in 4K and made a profit of 2 billion.
Investment = 550 million mining machines + 250 million bitcoins = 800 million
Revenue = 2 billion-250 million-800 million + 250 million = 1.2 billion
With an investment of 800 million yuan and a net income of 1.2 billion yuan, this is definitely not a good return for the Bitcoin industry.
How much benefit can be gained from an investment of 800 million
At present, 3,600 bitcoins are produced every day. If you keep 51% of the computing power, you can get 1,836, and you can get 55,080 bitcoins per month. The income is 200 million based on 4K calculation.
The 500,000 bitcoins held by the attacker, when the bitcoin price goes from 4K to 6K in a quarter, can get an extra 1 billion yuan. I think this kind of price increase is normal.