Today's cryptocurrency market plunge has ensnared the prices of several publicly-traded companies that in recent days have sought to tout their work with cryptocurrencies and blockchain.

Firms like Long Island Iced Tea (which this week declared that it would rebrand as "Long Blockchain Corp"), Riot Blockchain and LongFin are down, according to available market data.

The developments are a notable one, given that the past days have seen numerous reports about little-known firms – some of which specialized in the sale of, say, iced tea or electronic trading tools – that see their stock prices jump virtually overnight once they announce that they are moving to develop products or services around the tech. It's a state of affairs that has arguably raised eyebrows among some observers and sparked warnings from the SEC as well as groups like FINRA about the risk of pump-and-dump scams.

As it stands, many of those firms are witnessing declines as of the market opening today.

Long Island, for example, dropped more than 18 percent at the market open this morning, Yahoo! Finance data indicates.

Riot Blockchain is down roughly 7 percent from yesterday's close, after dropping sharply in a movement similar to the one seen in the Long Island chart.

By comparison, LongFin is down about 9.6 percent. Indeed, its decline is a notable development given that the price jumped sharply from $36.76 to $142.82 after it announced that it had acquired a company said to be focused on blockchain development.

To be sure, today's price declines aren't as severe as the ongoing correction being seen in cryptocurrency markets, as CoinDesk reported this morning. For a detailed look at some of the charts that show this morning's price action, click here.

At the same time, the public stocks are seen by some observers as a proxy for interest in – as well as the hype around – the tech by traditional investors. Whether these moves continue in light of the cryptocurrency drop remains to be seen.

Image via Shutterstock; Charts from Google Finance