Instead of investing so much in Hash power, just quarter of that $$$ to buy actual BTC and then you can control the market in much better way.
"quarter of that" = 1/4 * $8 bn = $2 bn @ $6,500/
BTC = 300,000+
BTC control the market?

maybe...
but wouldn't his buying frenzy willl pump the price? (eating up all sell orders)
then shortly afterwards price crash/correction/dump happens and gets him in a big loss