The Deal Book lists all your country's trades, as well as potential deals that did not happen because you rejected them or ran out of cargo holds. If a deal improved the diplomatic relations between the two countries it will be noted in the deal book.
From the deal book, you can access the markets scroll by clicking on one of the commodity icons on the right side of the screen. The information displayed here is for the turn that just ended.
The deal book also provides an end of turn summary, called the bottom line, that reports your profits or losses for the turn.
