How did mansa musa’s generosity with his gold affect the gold market?

Musa is considered by some historians to be the wealthiest man in history, and his wealth is estimated at an inflation-adjusted equivalent of four hundred billion US dollars in today's wealth.

Explanation:

Musa’s generous act was good for the people as he gave them gold but on the other side his action adversely affected the economy of the regions through which he passed  (Cairo, Medina and Mecca cities), a sudden flow of gold in these countries led to a devaluation (decreasing value of money) of the metal for the next decade.

Prices of goods and supply increased greatly. Apart from this, Musa did a great thing to reform the gold market as he purchased all the gold he could from the money-lenders in Cairo, at high interest rate so that the gold market can come in its old form.