After China, the South Korean financial authorities have also banned Initial Coin Offerings. Before knowing the reason, it is important to know what actually is ICO(Initial Coin Offerings).
Companies, in order to raise funds for their new business, offer their shares to the public at a price. This way, they acquire huge capital from the public. To date, companies like Alibaba Group, Facebook, VISA raised large sums of money this way. It helps companies getting a big start. This is known as Initial Public Offerings (IPO). When the same process is done by any Cryptocurrency, then it is called Initial Coin Offerings (ICO).
The reason why South Korea banned ICO is that they suspect cryptocurrencies to be sort of pyramid schemes, and thus they want to strictly control them. According to them, the cryptocurrencies are nothing more than a non-productive and a speculative product.
This step by South Korean Financial Authorities lowered the prices of Bitcoin and Ethereum by three percent, which have recovered by the time this post is published.