Since seeing it's price hit the $400 mark and crash back down to around $200 in mid June, Ethereum has had a quiet two and a half months with relatively little news. This has led to the stagnation of the ether price (stagnant compared to usual crypto price levels), with slow, steady growth trying to build back up to the $400 mark.
However, this uneventful preiod has seen bitcoin double in value since it's hard fork. Litecoin has hit the $90 mark, Monero, Nem and Iota have also seen large price rises.
This leaves Ethereum shrugging it's shoulders in terms of it's growth, but this could all change in the next month.
We have known for a while now that Ethereum will switch from a proof of work system to a proof of stake system. This time is now nearing, as Vitalik Buterin said that Casper could be activated by late 2017. Ethereums Metropolis hard fork will also activate in late September. This will pave the way for zk-snarks to be implemented, vastly improving the service.
I believe that these developments will lead to a sharp rise in the price that could drive the price of ether close to $500, maybe even further depending on further news that emerges and the success of the implemented new technology.