For me, this is a such a huge amount worth of Bitcoin to be moved in another address in only 15 minutes. However, it's still a mystery whatever the reason is.
These whales are just fortunate enough to accumulate Bitcoin during the early times. Until now, I still regretted in doubting about investing in Bitcoin years ago.
Correct me if I'm wrong, but these whales know what they are doing. They are here for the long-term since they have enough BTCs in their arsenal, especially the next year's halving. However, I would not really count on halving's guarantee of BTC's price pump.
It's likely not a whale but an exchange consolidating it's accounts. If they have a lot of dust they will move it to consolidate it into fewer addresses.
Most bitcoins are held at the major exchanges rather than in whales wallets.
It was an exchange, it was Bittrex. I did make me think though, since all of these wallets were hot for a period. I could only imagine what could happen to the market if there was a hack that big, it would be devastating.
I also assumed it was an exchange or another sort of company changing wallets to ensure the security or something like that, but since you're claiming it's Bittrex, proof would be nice. Anyway, I've googled it and I think I've found it, so I'm attaching it here:
https://cointelegraph.com/news/almost-9-billion-of-bitcoin-moved-on-chain-in-1-hour-record.
I don't think that whale alert makes sense, most of the time it turns out to be a technical operation... I don't even believe that there are 'whales' that can manipulate the market significantly, it's just a chain reaction with separate entities most of the time we see the price changing.