What is this chart?
A slope chart or (volume chart) is a visual representation of a marketplace.
The green represents people wanting to buy gold and the yellow side people wanting to sell their gold. In the middle, you see the price where they almost meet.
So in the above example, the lowest sell price (first yellow dot on the left) is 0.0975 bitcoin per gram.
The highest buy price (last green dot on the right) is is 0.095 bitcoin per gram.
The gap in the middle is called the spread. It is the distance between the lowest sell price and the highest buy price.
When a buyer (green) decides to go up in price to meet the sellers lowest sell price, then the market price will move up a bit. If the Seller moves down to meet the highest buy price then the price of gold moves down a bit.
The y-axis (up and down) is a number of grams that people want to buy and sell at their the different prices.
With this graph, you see how many buyers and sellers there are, what price they are willing to buy or sell for and how much volume they want to buy or sell.