Bitcoin mining vastly outpaces gold mining while price continues to grow (on average). Gold collapsing. Bitcoin up.
Time frame of reference. Bitcoin is up in the last 5 years, but gold has definitely outperformed bitcoin in the past year.
As far as stability, neither are. They're both subject to 5%+ price swings daily, which is far from stable. Just because bitcoin has temporarily found a price range in the low 2xx's doesn't mean jack. It has been following the same pattern of holding a price for a month or so then falling hard all the way from $700 and below. Until it shows a strong and maintained uptrend, the free fall remains.
The 30 day chart shows a +0.04% change. That is more stable than fiat.
I'm talking daily market changes. 30 day changes in such volatile markets are more coincidental than indicative of solidarity. Don't fool yourself.
These markets could and have crashed in a single day at whims notice.
Daily volatility against USD is just one metric to measure stability.
By such small changes as replacing the denominator USD in the equation with "purchasing power" (or the value of anything else but USD), or the "daily" for "any other time" you get completely different results.
Everybody who says dollar is more "stable" than gold is a sad, misinformed person. Dollar is stable strictly when measured in dollars.
As for Bitcoin, it is on track to overtake dollar's "stability" once it rises to any sustainable level first. The rise may take a longish time, because we are talking at 100x or much more.