But where is the mystery, the conspiracy, the drama...
Take a look at zerohedge and the comment section:
https://www.zerohedge.com/news/2018-02-15/bitcoin-tests-10k-mysterious-crypto-trader-dip-buys-400-millionBanks, governments, hackers...
Not that marketwatch is any better but at least they've said something like:
https://www.marketwatch.com/story/anonymous-trader-buys-400-million-of-bitcoin-2018-02-16“In the meantime, the $400 million whale is fuel for the Telegram channels where traders lay out their conspiracy theories,” said Jeff Koyen, president of 360 Blockchain USA.
Oh, and OP..
How is it unmasked when you don't have a clue who the "perpetrator" is?