I can admit that Lisk team will not do this. Max replied me :

"I think we are in a big liability if we start playing with the markets. That's why we bought our LSK off the market.
I think it's too risky, legally wise, to buy/sell on the market."

It is real demand for Lisk I guess. People realize that Lisk has huge potential and they saw Lisk team progress. It is also eth competitor. And too cheap. I am not surprise for this demand. Wait transparency report for this liquidated BTCs.