What is the ruling on selling a substance that was bought for 12,000 dinars per ton and stored for a year, then sold for 130,000 dinars per ton?

The forbidden monopoly (احتِكار) is to purchase goods when prices are high and people are in need of them, in order to increase their price further. However, buying goods when prices are low to sell them when prices are high is not blameworthy. There is no upper limit for the profit margin in trade, but a Muslim merchant should be lenient in their buying and selling, avoiding greed and selfishness, and observing ethical considerations.