The five ounce silver bar fill the significant gap in value between the 1 oz and 10 oz sizes.
They are efficient to make. Keeping fabrication costs low is the secret to lower premiums. Investors turn to bars because premiums (transaction costs) are much lower than for coins. They see the potential for silver bullion prices to go much much higher and getting more ounces for their money is the way to maximize those gains.
Gold
