"There is a very high degree of risk involved in trading securities. With respect to margin-based foreign exchange trading, off-exchange derivatives, and cryptocurrencies, there is considerable exposure to risk, including but not limited to, leverage, creditworthiness, limited regulatory protection and market volatility that may substantially affect the price, or liquidity of a currency or related instrument. It should not be assumed that the methods, techniques, or indicators presented in these products will be profitable, or that they will not result in losses." Learn more.
A pump and dump is when an organised group of people, sometimes 200 or even 1000 strangers, arrange to buy a specific coin at exactly the same time. This drives the price of the coin up, and when their desired profit is reached, they sell and the price falls again. The coin isn’t advertised in advance, only the time at which it will be. Sounds great, but in a zero sum market anyone making a profit equals someone making a loss.

Blockchains are secure by design and are an example of a distributed computing system with high Byzantine fault tolerance. Decentralized consensus has therefore been achieved with a blockchain.[29] Blockchains solve the double-spending problem without the need of a trusted authority or central server, assuming no 51% attack (that has worked against several cryptocurrencies).
A cryptocurrency (or crypto currency) is a digital asset designed to work as a medium of exchange that uses strong cryptography to secure financial transactions, control the creation of additional units, and verify the transfer of assets.[1][2][3] Cryptocurrencies use decentralized control as opposed to centralized digital currency and central banking systems.[4]