Bitcoin (BTC-USD) and most other major cryptocurrencies are deep in the red on Wednesday -- the latest in a two-week decline. In fact, all of the 25 largest cryptocurrencies by market cap (excluding Tether, which is based on the U.S. dollar) are down today.

Here's a look at the latest cryptocurrency prices and what might be behind this massive drop.

Gold coin with bitcoin symbols.

Image source: Getty Images.

Today's cryptocurrency prices

Here's a look at the 10 largest cryptocurrencies by market capitalization and how much each has changed over the past 24 hours. Bitcoin (BTC-USD) is down by more than 7% over the last 24 hours, and is actually the best-performing of the 10 largest cryptocurrencies. Six of the top 10 are down by double digits, and only three of the top 100 cryptocurrencies are positive on Wednesday. In short, this is about as broad of a sell-off as you can get.

Cryptocurrency Name (Code)

Price in U.S. Dollars

Day's Change

Bitcoin (BTC)

$7,594.90

(7.2%)

Ethereum (ETH)

$588.48

(11.8%)

Ripple (XRP)

$0.61

(8.4%)

Bitcoin Cash (BCH)

$1,027.70

(11.7%)

EOS (EOS)

$10.81

(16.7%)

Litecoin (LTC)

$120.66

(7.6%)

Cardano (ADA)

$0.21

(13.5%)

Stellar (XLM)

$0.28

(9.4%)

TRON (TRX)

$0.07

(10.8%)

IOTA (MIOTA)

$1.48

(14.5%)

Data source: www.investing.com. Prices and daily changes as of May 23, 2018, at 5:00 p.m. EDT, and prices are rounded to the nearest cent where appropriate.

Why are cryptocurrencies plunging?

There are a few possible negative catalysts. For example, some of the hype surrounding the well-publicized "Blockchain Week" in New York City may have bolstered prices, and now that it's over, we could be seeing lower investor interest.

Perhaps the biggest catalyst driving down cryptocurrency prices is regulatory fears.

Fears of increased global regulation have been the culprit in several big cryptocurrency sell-offs this year. The South Korean cryptocurrency saga in particular caused quite a bit of volatility.

This time, it's closer to home. On Monday, regulators in the U.S. and Canada announced "Operation Crypto-Sweep," which is being led by the North American Securities Administrators Association and has more than 40 states and provinces participating.

To be clear, the crackdown is focused on cryptocurrency investment schemes, particularly initial coin offerings, or ICOs. It is not targeting major cryptocurrencies such as bitcoin (BTC-USD) or legitimate businesses such as cryptocurrency exchanges. Even so, it seems to have the market on edge.

This comes on the heels of increased cryptocurrency scrutiny by the Securities and Exchange Commission (SEC), whose chairman has issued strongly worded warnings to cryptocurrency and ICO investors in recent months.

A good thing?

As I've written before, cryptocurrency regulation isn't necessarily a bad thing. Rather, it is the uncertainty surrounding regulation that drives the market crazy.

Regulation could be a good thing over the long term for cryptocurrencies. A regulated market would likely attract more institutional investors, and I don't think any legitimate cryptocurrency believer thinks that getting rid of scams is a bad thing for the industry. And, the implementation of global cryptocurrency regulation could help provide much-needed stability to the market, which could solve one of the biggest obstacles standing in the way of mainstream cryptocurrency adoption -- volatility.

In the meantime, however, it remains to be seen whether the current sell-off is nearing its end or if investor jitters will continue to send cryptocurrencies downward.