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 ??

Bitcoin protect people from inflation and maintain their wealth of because Bitcoin cannot be reproduce. It also protect people from corruption if it will be use in the government because Bitcoin transaction is transparent and can be viewed publicly.