$400 million USD is a lot of money...Who is the mysterious buyer? Charles Munger? Warren Buffet? US Government? FED? :)
According to BitInfoCharts, a mysterious buyer with a Bitcoin address of 3Cbq7aT1tY8kMxWLbitaG7yT6bPbKChq64 purchased an astronomical amount of bitcoins worth $344,000,000 at a blended cost basis around $8,400 from 02-09-18 through 02-12-18. In total, this Bitcoin whale doubled down adding nearly 41,000 coins for a new total of 96,000 coins worth somewhere around $900,000,000 at today’s price ($9,400).