To me the numbers never lie, the bitcoin dominance has been slowly falling over the last months and it is barely above 50% this means that overall altcoins have been more profitable during that time, also bitcoin once again surpassed our expectations and now it is trading for a price of 55k, I really think that some people were caught using leverage by the bears and this create a domino effect and that is what created such an important drop in the price.
But, never need to worry on these kinds of corrections and your probable reason of getting liquidated in leverage market definitely a reasonable one and this is why we never need to concern of getting to $55k region suddenly from $60k levels; just part of every market and bitcoin may bounce back at any time soon.
And in my opinion also, dominance in marketcap is just another number that most people are considering to compare and to take investment decision but honestly it is not having any economic value. I do never consider about dominance of bitcoin market and where it is heading.
I have no problems if that is your style however the bitcoin dominance is important to me because that indicates where we are in the market cycle, altcoins are now moving at an higher speed than bitcoin which means that speculators are now in control of the market, this has the consequence of having an increase in the volatility of bitcoin and altcoins and that now the market is behaving a little bit more irrational, which is exactly what we are seeing with the flash crash we saw a few days ago.