Per the rules set out in the Bitcoin whitepaper, the block confirmation subsidy (or reward) halves every 210,000 blocks. That’s generally every four years, and the next is estimated to happen on 14th May 2020. Originally 50 BTC per block, it dropped to 25 in 2012 and to 12.5 BTC in 2016. After May 2020, it will be just 6.25.
“Halvenings” have happened only twice in the past, in 2012 and 2016. Both happened before the initial 2017 hard fork split over block sizes, so there wasn’t a rivalry creating extra anticipation. While both saw Bitcoin increase dramatically in price in the next year or so, no-one can say for sure whether the halvening caused this… or whether it would necessarily happen again.
Reward halving will also occur on the BCH and BSV chains, since all three Bitcoin variants use the same original code and hashing algorithm. This is important because non-ideological miners can switch between chains easily, depending on which coin is most profitable.
Due to variations in block confirmation times since 2017, BCH will halve first and then BSV, before finally BTC. Please keep in mind this timing is subject to change. This is important because—for a few weeks at least—it is likely to be more profitable to mine BTC. This could lead to a drop in hash rate and possibly unit price for BCH and BSV, which may or may not be temporary.
Those are the main technical events to watch in 2020. Which brings us to the issues surrounding Craig Wright—some within his control, some less so. And here’s where we step into truly uncharted territory, meaning things could get really interesting.