In the Market you can buy or sell all resources ( Resource Production ), all Premium Currency , Slaves, Professors, Battery and Blueprint. You can see all your buy/sell offers and also your Market History in the last tab "My Offers".
Candlestick Chart (graph)¶
You may encounter a graph with blue/red bars going up and down while browsing the market. They symbolize the price change (upper blue/red bars) and transactions made (lower blue bars).
To learn how to read a Candlestick Chart, watch the following video: