Bitcoin gaining dominance is a good symbol for the bull run we can expect bitcoin to be back to previous prices once the price stabilises and prepare for next bull rally
Bitcoin dominance is been above 50% for last many months and that is why the altcoins are directly dependent on bitcoins. In such dominant bitcoin market, when ever bitcoin pump or dump, all other altcoins will have severe impact.
Thats why changes in bitcoin prices are very influential on the altcoin market, when bitcoin prices fall to tens of percent, many altcoins die because of that condition, the dominance of bitcoin is around 51% now, down several percent since prices fall, if prices rise their dominance can exceed 55%, that means the trend greatly affects the dominance of bitcoin