There are 2 updates on their way to Cardano’s mainnet. The first of which, Cardano 1.3.1, is scheduled to release during September 2018. The update will be comprised of little fixes that didn’t make the cut for the 1.3 release, but wouldn’t make sense to withhold any longer. After 1.3.1 is released, their Chrome extension wallet Yoroi will be allowed to enter testnet mode, and will soon thereafter enter its mainnet.
The proof-of-stake is a method of securing a cryptocurrency network and achieving distributed consensus through requesting users to show ownership of a certain amount of currency. It is different from proof-of-work systems that run difficult hashing algorithms to validate electronic transactions. The scheme is largely dependent on the coin, and there's currently no standard form of it. Some cryptocurrencies use a combined proof-of-work/proof-of-stake scheme.
By October 2009, the world’s first Bitcoin exchange was established. At the time, $1 was the equivalent of 1,309 Bitcoin. Considering how expensive Bitcoin is today, that was a real steal. Bitcoin traded at a fraction of a penny for quite some time. Things started changing in 2010; as the distribution of Bitcoin increased, the digital currency became inherently more valuable.