This is why regulation is important and very much necessary. OTC Block trades are extremely common when large chunk of shares change hands, bond markets are entirely OTC. IN equities, OTC trades do get reported, at least the volume. It is a regulatory requirement to ensure transparency in the markets.

Additionally OTC trades in these markets do not necessarily imply anything positive, if there is someone buying large volumes of btc at these prices, there may also be someone selling large chunks of btc at these prices. If the seller interest is higher, these large scale buy orders in OTC markets are probably getting filled sooner. Needs more data, the tweet.