First: all stock exchanges must be banned. While this is very difficult. Exchange a lot. They are scattered all over the world. There, where one exchange disappears, three or four new ones appear. Exchange, as well as crypto-currencies, open up on increasing. Certainly not all of them will live to old age. But the fact that there are many of them is a fact.

Second: you need to ban people. Suppose you destroyed the stock exchanges. But here a different problem emerges. People can act without exchanges, they can exchange goods directly: Fiat for bitkoyn, bitkoyn for fiat, goods for bitkoyn, etc. It is impossible to control 8 billion people.

Third: the elimination of the Internet. This measure may also prove ineffective. First of all, a lot of people will protest. Secondly, the Internet can be made extra-state or independent of decisions from above. Thirdly, even if the Internet is liquidated, it is not a fact that you are eliminating cryptonyms. Cryptography does not need to have Internet access. People can create Bitcoin 2.0 out of the Internet.

Fourth: buying all the crypto currency. Also it will not work, because it is known that even one bitkoyna suffices for the functioning of the world housekeeper. Let them buy it. It still does not work. Bitcoin is not gold. It can not just be taken and taken away, or braked at the border.

Fifth: counterfeit bitcoins through the liquidation of miners. This option is possible, if someone has the power of the network in their hands. Since the network is decentralized, it will be very difficult to find all the miners. But this, in my opinion, is the most realistic option, because the miners become larger and now they are easier to find. But even if you eliminate all the miners, this will not solve the problem. The discoverers can simply release another bitcoin. Well, you banned digital "gold", and what has changed? People switched to digital "silver"

In order for a payment instrument to be full-fledged money, it must perform the same functions as ordinary money (a measure of value, a medium of circulation, a means of accumulation, a means of payment, world money).

As can be seen, Bitcoin has all of the listed functions. It is known that like a dollar that is divided into cents, Bitcoin is divided into virtual coins (satoshi). The transfer of digital money is carried out by sending from one electronic store to another. The analog of the traditional wallet has cryptographic protection.

Hey! There are a lot of good projects  that you can find here   https://topicolist.com/

It remains for you to decide with which of these projects to work for you, good luck!

From which date does the payment start for investors?

I looked at your site and I think this is a good project - a blockchain for medicine.
I will invest in it

 
Bitcoin has inspired yet another technology that has some in the investor world worried that it will be used for the one thing bitcoin is commonly associated with: criminal activity.

Cryptocurrencies such as bitcoin remove the need for trusted third parties from basic monetary transactions and offer anonymous (more accurately, pseudonymous) transactions between individuals. While attractive to some, these features have a dark side. Bitcoin has stimulated the growth of ransomware, money laundering, and illicit commerce

There is always any risk, doesn't matter what you do. As for me i would rather make a few portfolios. So you will not lose all ypur money if bitcoin crashes.

Before you start investing in crypto currency you must do two things: 1 is to study the process of handling bitcoin.
                                                                                                     2 Understand the "pitfalls" of such investments.

There must be a correction after that rise. However, some people are definitely sure that the price is gonna be over $10000 by  April 2018.
The bitcoin bull market may be reaching a point of exhaustion.
After the cryptocurrency printed a fresh record high of $7,454.05 on Coindesk's Bitcoin Price Index (BPI) earlier today, BTC has failed twice to hold above $7,400 mark.
All in all, we cannot be sure, the price may go up or even burst like a babble

It seems the recent success of digital currency has attracted the attention of the ill-intentioned and criminally-minded.

Apparently, malicious agents have been attempting to benefit from the increased interest in Bitcoin and Ether through phishing and typosquatting tactics. In essence, people have been setting up fake sites with typographically similar URLs to legitimate bitcoin wallet download websites. 

These phony sites have not only shared typographically similar URLs to legit sites, but they have been made to look visually the same as the pages they are mimicking.

One such example is that of blocklchain[.]info, a site made to mirror Blockchain.info, a popular bitcoin wallet provider. This particular example was discovered by the cloud-based Israeli security-firm, Cyren, after observing the domain spreading through a pay-per-click advertising scam via Google AdWords.

Well, that's a good question because China was a primary driving force in Bitcoin due to its large market share in trading and mining. The world’s greatest consumer-grade ASIC miner is in China. Chinese manufacturers and suppliers specialize in designing and manufacturing Bitcoin mining hardware. Sichuan Province is full of Bitcoin mines due to its cheap electricity. Miners in China are believed make up more than 60% of the Bitcoin network's computing power. China was also the main reason that Bitcoin price has been going up.