You are right, the cryptocurrency starts with Bitcoin, the first cryptocurrency, and it is also the king of the entire investment market, and its technology is widely recognized. All altcoins are valued with the value of bitcoin.
There's no doubt about it because crypto industry will get known worldwide with the technology behind of bitcoin. Because bitcoin was the first known cryptocurrency investment that more investors were already tested it and believed it as well. So with bitcoin price volatility behavior all altcoins also will varies and are fully depending of its market value trends.