Possibly this  wallet could be a wallet belonging to an exchange or an organisation trying to make a change of vault  as this amount is some how big and risky for an individual to hold at once in a particular wallet. I strongly believe a new generational exchange can not hold or have such a large volume of bitcoin in their possession coming third behind Binance and Bitfinex well known to be the exchange whales holding such large amount of bitcoin. With time, the real owners of that wallet would be known and my guess would not be wrong.