Gold and silver are hedge against inflation/price rise and they protect people's wealth during wars, natural disasters such as Earthquakes, hurricanes, cyclones, economic crisis, 9/11 terrorists attack etc.. so gold and silver are a store of value.
Stock markets are indicators of sales in the economy. When there is sales for the company as per study, they are profits and share price rise. if there is loss, the share price falls.
As a commodity, what does Bitcoin price show or protects people from ??

For me, bitcoin protects people from being scammed by other banks or hackers. Since bitcoin is secured, it lessen the chance of being hacked by hackers or scammed. It also protects people from being greedy.