Looking at the charts I see that the bull run started in 2016. We went from 200$ all the way up to 1000$ at the end of this year. The price went parabolic the whole 2017 because of many good news that had to do with adoption. These news became reality with Bitcoin becoming a legal method of purchasing in Japan and Korea and then these major markets started investing. So I don't think it was the halving caused the price to rise this high.
I don't know where you look at the data, but if you check
here then you can see that the price on Jan 01, 2016 was around $400+, and it stays at that level until May 2016. The year is closed with $960, and I do not see bull run in 2016, perhaps only his beginning.
I know that Japan is declared BTC as "form of payment method" in 2017, but where you get info that South Korea is doing the same? To my knowledge, this has never happened, and 2017 was not a positive year as far as it was concerned crypto regulation in that country.
In South Korea, cryptocurrencies are not considered legal tender and exchanges, while legal, are part of a closely-monitored regulatory system. Cryptocurrency exchange regulations in South Korea are strict and involve government registration and other measures overseen by the South Korean Financial Supervisory Service (FSS). Although a rumored ban never materialized, in 2017, the South Korean government prohibited the use of anonymous accounts in cryptocurrency trading, and also banned local financial institutes from hosting trades of Bitcoin Futures. In 2018, the Financial Services Commission (FSC) imposed tighter reporting obligations on banks with accounts held by crypto exchanges.