"When the quantity of any commodity which is brought to market falls short of the effectual demand, all those who are willing to pay... cannot be supplied with the quantity which they want... Some of them will be willing to give more. A competition will begin among them, and the market price will rise... When the quantity brought to market exceeds the effectual demand,  it cannot be all sold to those who are willing to pay the whole value of the rent, wages, and profit which must be paid in order to bring it thither... The market price will sink..."

To paraphrase Smith, and the first part of this Chapter, when demand exceeds supply, the price goes up. When the supply exceeds demand, the price goes down.

He then goes on to comment on the different avenues that people can take to generate a larger profit then normal. Some of those include: finding a commodity that few other have that allows for a high profit, and being able to keep that secret; Finding a way to produce a unique commodity (The dyer who discovers a unique dye). He also states that the former usually has a short lifespan of high profitability, and the latter has a longer. He also notes that a monopoly is essentially the same as the dyers trade secret, and can thus lead to high profitability for a long time by keeping the supply below the effectual demand.

"A monoply lanted either to an individual or to a trading company has the same effect as a secret in trade or manufactures. The monopolists, by keeping the market constantly understocked, by never fully supplying the effectual demand, sell their commodities much above the natural price, and raise their emoluments, whether they consist in wages or profit, greatly above their natural rate. The price of monopoly is upon every occasion the highest which can be got. The natural price, or the price of free competition, on the contrary, is the lowest which can be taken, not upon every occasion, indeed, but for any considerable time together. The one is upon every occasion the highest which can be squeezed out of the buyers, or which, it is supposed, they will consent to give: the other is the lowest which the sellers can commonly afford to take, and at the same time continue their business."