One thing is certain, if I had uncovered any major amount of Bitcoin from the early days, I wouldn't share it on the forum, for obvious reasons. This wallet could belong to a holder, a miner, or even some average joe who had bought Bitcoin in 2010-2012 and decided to cashout their coins now, after recovering their long-lost wallet. There's a large number of dormant wallet addresses, of which unfortunately a large amount of Bitcoins have been lost forever, reducing the number of circulating coins in the market.