This past weekend has seen a significant dip with all cryptocurrencies, not only Bitcoin. Bitcoin, at one point last week surpassing $4,900 per coin, has now dipped to around $4,000 per coin. NEO has also seen a significant dip, plummeting to below $20 from over $50 a few weeks ago. The main reason given is that Chinese regulators have banned all new organizations raising funds from ICO's. As it is, this isn't the first time the pesky Chinese affected Bitcoin and all cryptos. Earlier in March they announced they were going to consider clamping down on trading, which caused Bitcoin back then to dip as well.
Some investors though are saying that this recent dip is short-lived and will pick up soon. This is what's happened with previous dips and therefore it stands to reason that this is what will happen again.
There may be another reason Bitcoin and all cryptocurrencies dipped though: Labor Day weekend. Much of the U.S. and Canada have celebrated by spending more time with families and less time trading. It's likely that the dip in trading caused a dip in the value of cryptocurrencies, which is primarily based on supply and demand. Once trading becomes more frequent again, we should expect another rise in Bitcoin and all alt-coins, which will overshadow any Chinese regulation on ICOs which has no bearing on what currently exists.