Currency as an exponentially increasing investment is not sustainable. I believe we're seeing and experiencing the BOOM of a new form of currency entering the world and gaining awareness.
Supply and demand tells us that as a limited supply of this currency (BTC, ETH, LTC, DASH, etc.) exists, and as more and more people want to get in, the price will go up. It will continue to climb (perhaps exponentially) until everyone that wants to get in is in. Then we'll see a "final" correction to where the currency will remain relatively stable. If by the time I get my paycheck in-hand it has already changed value significantly, I'll demand that I am paid in another currency. Bitcoin as it stands is not stable enough for widespread use... until it stabilizes. In the meantime, fortunes will be made and lost.
Do not invest what you're not willing to lose! Stay safe. Cryptocurrency (for now) is a game -- games make winners and losers. Winners are the ones with the best strategy, and sometimes strategy involves taking calculated risks.
