Please be aware that the price chart displayed before the mainnet's launch refers to the price of the EFYT (Ergo-First-Year-Token), which was exchanged 1:1 for the ERG. EFYT served the dual purposes of raising a small amount of money for the platform and building an early community prior to launch to fund development, promotion, etc. Find more details here.
The Ergo platform aims to provide an efficient, secure, and easy way to implement financial contracts that will be useful and survivable in the long term. Ergo describes itself as a self-amendable protocol that reportedly allows it to absorb new ideas and improve itself in a decentralized manner.