Chart below is a combined cumulative order book view. At the top right of this message you can switch horizontal axis to display selected currency or a relative value. Relative value shows price change as percentage.
E.g. for exchange foo with the middle price point of $100, 1% value is the same as $101 in the currency view. Note that the same percentage will translate to different prices on different exchanges.
Vertical axis unit is BTC. It displays sum of orders below given point (for asks, or above given point for bids).
You can click to lock the tooltip in place (and click second time to unlock it).
Because of that, data updates have been paused to save your resources.
Bars below show sum of orders between current price (mid) and price +-1 %. Instead of 1% you can choose different value with the select in the top left. In the top right you can select currency.
Values displayed on the bars are in BTC.
Gap in the thin line under the exchange name is proportional to how big the spread is on a given exchange (i.e. smaller is better)
When you mouse over the exchange name, top chart will display more detailed view of order book for the selected exchange.
Green triangle up or red triangle down appears when trades are happening on a given exchange.