I didnt expect any pump today and felt bitcoin is already price-in, i also felt traders will be watching than selling and more activities for miners, it was a very busy day for miners who want to take their share from the last period of 12.5 bitcoin from each block. I dont think bitcoin halving has ever caused this pump, it caused more dump in short term before a gradually movement. Due to the global market condition I cant predict the movement of altcoins.
I'm sure traders will be looking at bitcoin price against what altcoins they are hodling or buying. I predict that this bitcoin halving will favour more of altcoin because unlike in last halving, the numbers of altcoins now have increased and some nice project are existing.
At the current price of Altcoin I am sure it will tempt whales to enter, because if they enter and the pump arrives they will get more Bitcoin, and if Bitcoin PUMP then they will get more money