How is this data calculated? Is this the global stock market or limited to the US? If this is global data I can see people twist the narrative that the stock market is open 24/7 too.
The point is that there is no ONE stock market. You can compare it with the one you want. If you compare it to the NYSE which would be typical it will give you that and if you compare it to another country's, the same thing. What you can't do is say that the stock market is open 24/7/365 because what is open at that time are different stock markets.
I have stocks and mutual funds that I can't trade when the US markets are not open, although I can trade in other stock markets but bitcoin I can buy and sell at any time.