I'm not an economist but this is what I have gleaned. There could certainly be other factors not accounted for.

Silver is mined out of the earth at the same rate as gold. It's used in tech way more than gold. The investor class buys gold not silver, this keeps the price of gold lower then real value but closer to what it should be, unlike silver which is many time less then the value of gold. The poor buy silver, but the poor don't ever have extra money, the poor have nothing to do and have pockets full of cash now thanks to the shut downs, they are also pissed as shit if they are aware of what's up, and just got more free money from big daddy warbucks. Not to mention crypto gains. Now they are told that what they do anyway can destroy the economic system. The banks manipulate the metal markets to hide inflation. When the investor class realizes the real value of silver should be at around the value of gold because of its rarity and use they will buy with out hesitantion and drive the price up to fill out their portfolio and hold a position. This makes up part of theory as to why silver is skyrocketing. The other of course is the relationship to short sales and GME which has served as the spark to ignite the economic bomb and bring it into the zeitgeist. So gold is undervalued sure, but silver may be undervalued by a lot more especially considering its position to be over sold. The question is by how much? If it is a few time, the price might only double. If its totally fucked and more like a 1000 times over sold... To the moon.