£684,000 of Arsenal Shares Traded Today. Who & Why?

Today 40 Arsenal shares were traded on Plus Markets, 20 at £17,050 each and another 20 at £17,150 each (the record high price is currently £17,250 per share).
The reason this is worth talking about is that trades of more than one or two shares at a time are unusual these days – the last time 40 or more were traded in a single day was in October 2011, the time before that in July 2011. Recently as few as three shares have been traded per month.
Who bought these shares?
At the moment we don’t know. We know for sure it’s not a member of the Arsenal Board (of which only Stan Kroenke currently holds any shares), as Board members must make a public declaration via the stock exchange when they buy or sell any shares in their own company.
There is of course a prime suspect as a buyer: Alisher Usmanov. For r...