Israel’s financial regulator has announced proposals seeking to effectively ban companies dealing in Bitcoin from listing on the Tel Aviv Stock Exchange.

Shmuel Hauser of the Israel Securities Authority made the announcement at a conference early this week, suggesting the proposals would be formally brought forward to the regulator’s board next week.

While the provisions are still subject to approval, involving a public hearing and subsequent amendment of stock exchange regulations, they indicate a clear direction for the regulator in tightening the laws around companies engaging in cryptocurrency business.

There are at least two companies listed on the Tel Aviv Stock Exchange that would be directly affected by these provisions, namely Fantasy Network and Blockchain Mining, with the potential for others to be caught by the proposals.

Addressing the need to find fresh regulation for these companies, Hauser was unequivocal in his stance.

“If we have a company that their main business is digital currencies we would not allow it. If already listed, its trading will be suspended,” he said.

Blockchain Mining changed its name and business focus as recently as last Sunday. Formerly known as Natural Resources, the firm has now pledged to shift its focus from mining for iron and gold to mining for specific cryptocurrencies, in a move that seen its share price soar some 5000%. However, on the news from the regulator, its shares were down 4.2%.

Fantasy Network, formerly specializing in gaming, announced its own further exploration into the blockchain space, causing its own share price to grow by 400%. Similarly, it lost 50% of its value over the last few weeks, with the regulator’s plans no doubt weighing adversely on the price.

Still, Hauser remains undeterred, and confident that the ISA approach is the right one, in terms of protecting investors and offering certainty to companies.

“We feel that the prices of Bitcoin behave like bubbles and we don’t want investors to be subject to that volatility and uncertainty…There is an importance to signal to the market where things are…Investors should know where we stand,” Hauser said.

The proposals are regarded as the last significant move from Hauser, as he prepares to stand down from the ISA next month.

It remains to be seen whether the new regulations will gain the necessary approval to be written into Israeli law.

New to Bitcoin? Check out CoinGeek’s Bitcoin for Beginners section, the ultimate resource guide to learn more about Bitcoin—as originally envisioned by Satoshi Nakamoto—and blockchain.