Vikings is not a particularly realistic show just like much off the image off vikings amongst people.

Vikings were excellent traders as they were fearsome fighters. They traded from Dublin to Baghdad. They generally prioritized valuable trade goods, items, clothes and food too. The most valuable trade good of all was slaves. Vikings supplied much off Europe and Arabia with generally slavic slaves. Slave word comes from Slav, because Vikings traded so much off them. Anyways pop culture tends to show Vikings only as people who only just plunders valuable metals and kills for fun, but they were more than that. So no, they did not only loot gold and silver.