It appears it might be Tim Draper auction but why would they not touch these coins back in Q4 2017 or at least sell them at $14K a month ago instead of selling now?
It's impossible to tell who these addresses belong to, but it wouldn't surprise me if the coins are moved to another address for the sake of liquidating BCash, BSV, BTG, etc.
Don't forget that a lot of people during the split thought it would be a safe bet to hold the forks just in case they take over Bitcoin, but after such a long period of time and the poor performance of these scams they gained enough confidence to unload them.
If the coins are being moved to be sold then I only welcome that. The more of these old hands unload their coins the more distributed the coins become, and the higher the base value of these coins becomes. People who bought their coins under $100 don't really care if it's $9000 they sell it or $14,000. It's a massive profit either way.