The halving, the logic behind the cut in half of the reward is coded in the source of coin itself, that is the place to begin with. Offcourse there may be some website with a complete list out there already but i don't know any.
Exactly my thought, the market is pretty easy to make a chunk off of if you plan a month or two in advance of a major coin halving, especially if LTC follows suite here, then BTC will be a big payday this winter. Heck I bet people would "donate" a little for a continously updated list of estimated halving dates based on hashrate, hashrate over time, blocks to next halving etc.
Edit: I spoke to soon, this isa the exact site I was looking for the otherday when I lost all my bookmarks to all my data for analysis
https://walletinvestor.com/forecast/bitcoin-prediction they have it for all major coins it looks like I never noticed thayt and I've been using their bull/bear meter for ages.