I dont consider the halfing bullish or bearish
It certainly can't be priced in beforehand because its very much unknown how it will effect the network
On one hand we have half the supply, on the other hand chaos may ensue if miners become drastically unprofitable and hash rate drops accordingly.
so my thinking for halving halfing? is that we will price it in after the fact, if it goes well UP, if SHTF down.

personally i think everything will be just fine, we MIGHT have a small temporary drop in hashrate but Shit will not Hit The Fan. not really willing to place a serious amount of money either way tho.