Why do you think so many altcoins are falling so rapidly, when Bitcoin is doing so well and crawling towards new highs??
Given it was issued with proof-of-work, Bitcoin is not a security and thus is not impacted by the ban on ICOs in China and South Korea, and the enforcement actions on ICOs that the SEC and Australia have already announced.
Also recent news has indicated that China’s ban on exchanges will not impact Bitcoin in every facet, i.e. there will be no ban on mining nor on transacting in BTC.
I do expect the other proof-of-work issued altcoins to catch up with Bitcoin, including eventually BCH and XMR. LTC has also been rising along with BTC.
Actually some of the alts have also risen a lot in past few days, such as NEO and STEEM.
In general, BTC tends to lead alts on the way up, and alts catch up as BTC’s rise matures (as some people diversify their BTC gains into alts).