Ethereum network slows to a crawl as EtherDelta is unable to keep up with the demand for new ERC20 token ZRX starts trading on the only platform available EtherDelta.
Half of the day EtherDelta was showing peoples token and Ethereum balances as NaN. This means that the EtherDelta network was not functioning properly and the balances were zeroed out for the time being. Once EtherDelta came back online, balances were restored.
Even now, you cannot get an accurate order book reading from EtherDelta as it is not able to keep up with the speed at which transactions are occurring and therefor the order book is lagging significantly. This makes it very difficult to make any successful trades or get a feel for what actual market prices are.
The OX offering is so popular it has heavily influenced the Ethereum netowork and the EtherDelta platform for trading tokens on the Ethereum netowork by slowing them to a crawl.