Gold is at from stable. There is plenty of volatility in gold prices. Compared to Bitcoin it may look more stable, but any gold chart of sufficient length will give you enough data to see that gold suffers from volatility in the short run.
At least when compared to Bitcoin, gold is far more stable. One of the reasons is that the market cap of gold is between $5 and $6 trillion, while that of Bitcoin is less than $15 billion. So for a 1% change in the gold price, there must be at least $50 billion worth of market cap change.