What happened 

Cryptocurrencies continue to have a wild trading week, and Thursday there are sharp moves both moves higher and lower. According to Coinbase's price chart, Bitcoin (CRYPTO:BTC) is down 4.5% over the past 24 hours as of 11:30 a.m. EDT and Dogecoin (CRYPTO:DOGE) is off 2.5%, while Ethereum (CRYPTO:ETH) is up 1.6%. 

Taking a bit of a step back to price movements over the past week, the picture looks little better for cryptocurrencies. Bitcoin is up 9% over the past week, Ethereum is up 11.7%, and Dogecoin is up 4.1%, which shows a much more bullish picture than the price movements today. 

Digital representation of a Bitcoin.

Image source: Getty Images.

So what

Bitcoin is coming off highs from Wednesday that were driven by the ProShares Bitcoin Strategy ETF (NYSEMKT: BITO) officially reaching the market. Investors have been bidding up Bitcoin, in particular, in anticipation of this exchange-traded fund, and that's pulled a number of cryptocurrencies higher today. 

In a sign of just how critical this ETF has been to the crypto trade short term, Bitcoin peaked near $67,000 just an hour after the market opened on Wednesday and has been falling ever since. For Bitcoin at least, this looks like investors buying the rumor and selling the news. 

The general trend for all cryptocurrencies over the past week has been higher, and that's in large part because investors see advances like ETFs and regulation from the Securities and Exchange Commission as positive moves for the adoption of cryptocurrencies long term. The industry has been looking for broader legitimacy, and if more and more investors and institutions have exposure to crypto, it will make it harder to squash the industry, as China has tried to do. 

Now what

This week has potentially been a significant one for legitimizing cryptocurrency long term. If Bitcoin and other cryptocurrencies are traded in commonly known products like ETFs, it will bring more people into the market, which would be good for the industry. That doesn't mean prices will continue to go up, but it may mean that the industry has a little more staying power as more people are using these products. 

I will also point out that volatility like this has become normal for cryptocurrencies long term and especially over the past 12 months. So, this could simply be volatility based on speculation, and in the next few weeks we could see a sell-off as speculators leave the trade. 

No matter what is moving crypto today, I don't think there's a reason to change your investment thesis long term. The industry is still maturing and finding use cases and ways to add value. That will likely lead to more volatility as speculators enter and leave the market, but the important thing is building fundamental use cases or other sources of value for investors. ETFs are one sign that legitimacy is on the way and looks positive for cryptocurrencies long term. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.