Volatility only seen once before
A correlation between events of January '18 and June '17
Smart people have brought attention to the fact that no currency lasts forever and one day Bitcoin will lose its dominant position, probably to Ethereum. This day in the hypothesized future is referred to as a very special event known as the flippening. The flippening of Bitcoin and Ethereum is believed by many, including myself, to be approaching. The theory relies heavily on a belief that Ethereum's core development team is superior, their platform is better, and the technology will simply win. Time and history will reveal the truth to us.
It is then with great attention to market dominance that speculators watch Bitcoin fall from grace with Ethereum's rise. Remembering that Bitcoin started with a monopoly on cryptocurrency, we must now look at every passing day as it declines. As of this writing, Bitcoin's position is about 32% of the total market while Ethereum stands at 18%.
In June of 2017, Ethereum's position was 31% at its highest and Bitcoin was 41%. This time period was, so far, the closest Ethereum has come to overtaking Bitcoin's dominant marketcap position. This time period is also peculiar in that it was a period followed by extreme volatility and a market slump. With a sample size of one, we cannot know much for certain -- but we do know that the flippening was close and it was followed by volatility.
In January of 2018 an event occurred that has only ever happened that one time before: Ethereum surpassed an exchange rate with Bitcoin of 1 BTC to 10 ETH. The last time Ether's exchange rate approached such a level was June of 2017. As with last time, Bitcoin volatility has resurfaced and hit the markets. While correlation does not equal causation, I do think that there exists a connection between Ethereum's relative rise and Bitcoin's momentary volatility.
Big changes in the world are often violent and volatile. We know this to be a truism of history. In the cryptocurrency world, we should have some level of expectation that big changes in Bitcoin will lead to volatility as cards are reshuffled. Bitcoin has always been the standard of measurement for this market as the currency has always held the number one position. The Bitcoin advocates of our day typically shame people who pay any attention to alternative cryptocurrencies that they refer to simply as "alts".