I had estimated
something similar for the end of 2017 because of Argentina introducing a cryptocurrency tax (more precisely, including cryptocurrencies into taxable assets for capital gains tax if your profit is larger than ~2500$/year).
Well, and there
was definitively a sell-out in December
But I don't think these sells to try to prevent taxes can lead to more than a very limited price dip. While the US is certainly more dominant in the "crypto world" than Argentina, I think they aren't dominant enough to drive the price down for a longer time, and most people will try to hide their BItcoins anyway.
Instead, it seems that the $6500 level has been tested well now and price is going up again. I don't think it will be a complete recovery up to December levels, but next week could be bullish or the price could go sideways at least.
BTW: I think there is an error in the title - wouldn't make "investors" instead of "exchanges" much more sense?