If you're not a miner, the halving shouldn't have much effect. 14.5 million of 21 million bitcoins have already been mined. Everybody knows this event is coming, so it should already be priced in.
If you are a miner, then you're running spreadsheets to see what equipment to keep, what equipment to dump, and what equipment to buy. Much of the older gear will be junked at the halving.
I think precisely because of the fact that everyone is expecting something, even if it's nothing, but everyone has the halving date on their minds, because of this, a huge pump can happen. The market game is a psychological one after all, psychology defeats all possible TA.