After a two-day "crypto crash," major cryptocurrencies are rallying across-the-board today. Bitcoin (BTC-USD), Ethereum (ETH-USD), and Ripple (XRP-USD) are all up by more than 20% since yesterday's lows, and have added to their rebounds throughout the morning.

Today's cryptocurrency prices

After several days of dismal performance, all of the major cryptocurrencies are well into the green today. In fact, bitcoin is the worst performer out of the major currencies, and it's up by 22% over the past day.

Stacks of gold coins with bitcoin logo.

Image source: Getty Images.

Here's a look at the five largest cryptocurrencies by market capitalization, and how much each has changed over the past 24 hours.

Cryptocurrency Name (Code)

Price in U.S. Dollars

Day's Change

Bitcoin (BTC-USD)

$11,600.00

21.7%

Ethereum (ETH-USD)

$1,044.50

28.1%

Ripple (XRP-USD)

$1.54

55.4%

Bitcoin Cash (BCH-USD)

$1,817.8

23.8%

Cardano (ADA-USD)

$0.66

36.2%

Data source: www.investing.com. Prices and daily changes as of 9:30 a.m. EST on Jan. 18, 2018, and prices are rounded to the nearest cent where appropriate.

As you can see, bitcoin (BTC-USD), Ethereum (ETH-USD), and Ripple (XRP-USD) are all soaring today, and are back above the key $10,000, $1,000, and $1 price levels. Ripple, in particular, is rising rapidly, which makes sense since it has been one of the worst performers during the recent price drop.

It's also worth noting that while cryptocurrency prices are indeed soaring today, all five of the currencies in the chart are still negative for the week. Over the past seven-day period, bitcoin has fallen 15%, Ethereum is down 14%, and even after its big move today, Ripple is still down 19%.

Why have cryptocurrencies been so volatile?

Volatility in the cryptocurrency marketplace is nothing unusual -- digital currencies regularly experience large price swings. However, the past few days have been uncharacteristically volatile, even for the crypto market.

The main driver of the past two days' declines was fears about global regulatory changes. Specifically, South Korea's finance minister announced plans to push for a ban on cryptocurrency trading, and China announced its intention to crack down on cryptocurrency trading even more than it already does.

It seems that the market may have overreacted, as buyers seem to have come rushing back in, which is helping to boost prices.

Is cryptocurrency regulation such a bad thing?

Regulators around the world have expressed their concern over cryptocurrencies and ICOs. Considering the surge in popularity over the past several months, it shouldn't come as a surprise. While it may be nerve-racking to hear about regulatory changes that may or may not happen, over the long run, getting more clarity on cryptocurrency regulations could be a good thing for the industry.

I've written before that one of the biggest obstacles to cryptocurrencies gaining widespread traction as both a payment method and store of value is its volatility. And one thing the last few days have shown is that the prospect of regulatory changes around the world have the ability to take cryptocurrency prices on a wild ride.

From a long-term perspective, regulations could help stabilize the cryptocurrency marketplace. If investors, traders, and consumers know exactly where governments stand on cryptocurrencies, it will obviously be a lot easier to factor regulations into prices.

In short: Cryptocurrency regulation isn't necessarily bad. Uncertainty surrounding cryptocurrency regulation is.

Matt Frankel has no position in any cryptocurrencies mentioned. The Motley Fool has no position in any cryptocurrencies mentioned. The Motley Fool has a disclosure policy."