Cryptocurrencies have no tangible underlying assets, and thus trading in them is speculative by definition.
All stocks on Serenity are updated as and when their prices and other data change.
Thus stocks updated on Friday will display 3 days in their Last Updated field on Monday.
Stocks that are no longer traded are also retained on Serenity for informational purposes.
But since they can no longer be updated, they will display larger time periods in their Last Updated field.