First of all, there are huge threads about cryptocurrencies already, do skim through them.
Bitcoins - digital currency
Virtual Currency - Alt Coin Discussion Thread
As with any investment, the high potential reward from trading cryptocurrencies comes at a big price - the high volatility. If not for the risk, of course, everyone would invest into them instead of bonds, stocks, commodities and other officially approved assets, but only a small fraction of the world population does, mainly because there's a huge political risk.
Cryptocoin holders are basically making an anarchist political statement - that they'll be able to build an efficient alternative global financial system circumventing the governments. Of course, the governments are hating this with passion.
One of the reasons, pitched to the public as the main official reason, is that alas, by their very design, cryptosystems allow criminals to easily get money covertly. But the real main reason is of course that the governments want to tax as big a portion of the economy as possible and are hating the emerging black market.
In particular, this March, the Ministry of Finance of Russia proposed to make cryptocurrency possession a felony, but on October 13-14 at the Finnopolis 2016 forum in Kazan, it was stated that it's not going to be punished yet, which appears to be one of the minor reasons for the recent Bitcoin rally.
Every statement by any major government about its intentions to control or restrict the use of cryptocurrencies might cause a crash of their x-rates for fiat currencies or at least make transaction costs higher (as the costs of maintaining conspiracy will go up).
If Bitcoin chooses to cooperate with the major governments, then it will lose its intrinsic value as an 'under-the-table' currency, which is a big component in the demand for Bitcoin: if it were just another version of traveler's checks with no capacity of bypassing the official financial system, it wouldn't be worth hundreds of dollars per unit.
Therefore, it's advisable to invest only a small, if any, fraction of a personal portfolio into cryptocurrencies.
Last edited by coon74; 12-23-2016 at 06:35 PM.