Gold “massively outperformed” due to many risks and on the expectation of major financial crisis and had as such had priced in the financial crisis of 2008 and protected investors during and after the crisis.
Silver is much more volatile than gold. Typically when we see a weak day for the gold price, silver has a terrible day. Likewise, if we see a strong day for gold, typically silver delivers exceptional performance. Because it's so volatile, we term it the devil's metal.