The market overview lets you quickly compare price movements on different timescales.
The overview shows three gauges, for the price movement during the last 60 minutes, 24 hours, and 5 days. Each gauge shows the current price in relation to the high-low range (with prices). A gauge which is mostly blue means that the current price is towards the top end of the range; orange means that the price is towards the lower end of the range. The inner bar then shows the open price for the period, and the corresponding % change.
Below the gauges are three simple candle charts, letting you compare short-term market activity on the M5, M15 and H1 timeframes.
The BTCUSD pair is the abbreviation of Bitcoin against the US Dollar. Bitcoin is the cryptocurrency that has the biggest nominal market price and the largest market capitalization. It is considered the main Cryptocurrency whie all other digital currencies are treated as Alternative Coins (altcoins). BTC is commonly valued in terms of the world's reserve currency, the US dollar (USD). Volatility has constant presence in the BTCUSD valuations, with prices fluctuations of 5% or 10% of the value within a 24 hour period. BTC is in its infancy compared to the USD with high skepticism amongst traders as the digital currency has limited supply and the regulatory status is yet to be defined. Questions about its security have also been raised. While traditional currency market influences such as central bank decissions or economic news do not affect BTC directly, the USD remains subject to all of these factors and it can affect the pair.