Bitcoin’s price fell after rising over the weekend to its highest level since May, according to Bloomberg. The popular cryptocurrency fell 4.9%, while over the weekend it had managed to exceed $40.000. Other cryptocurrencies such as Ether, which is the second largest cryptocurrency, are also declining.


This is “just a normal pullback of the bullish action that has taken place,” said Vijay Ayyar, head of the Asia-Pacific with Luno cryptocurrency exchange in Singapore.


The falls bring Bitcoin back to the $30.000 – $40.000 zone that has been in place since May. On Sunday, however, bitcoin reached $42.605, which is the highest level since May.


Comments of Elon Musk and Cathie Wood from Ark Investment, as well as speculation about Amazon’s possible involvement in cryptocurrencies, contributed to the rise of Bitcoin.


At the same time, scrutiny of the cryptocurrency industry is intensifying as US legislators push for tougher rules on cryptocurrency investors, in order to raise more taxes and fund some of the planned $550 billion investment into power systems and transportation.


Cryptocurrency traders are also expecting a software upgrade this week, on the Ethereum network, which could increase the price of Ether.