Actually, I don't think that many people bought a huge amount of Bitcoin in late 2017 because the price was so high at that period probably some newbies made that mistake. Also, it is sure that the whales was the reason for that huge dip. To be honest, if someone for real bought a lot of BTC in that periode, then it is pretty certain that he is still losing money especially if he does not have a continuous financial income with BTC or cryptocurrencies. Now, it is really sad the current price is under 10K hopefully, everything will be better after the halving event.
The price moves high for just a few months because of high demand, people are coming just to invest Bitcoin and other crypto making a way to move the price continuously. Because they'll think that it will keep soaring but unfortunately, the moves of some whales hype had stop and result to lowering down the price. But, some people are still optimistic and hold currently hold their Bitcoins until today, if that so I don't think that they are still profiting coz definitely, they are still not in gaining.
Those who can sell their coins at the first drop of Bitcoin will still get some but those who did not, then it will be so sorry.