This is a very simple GNOME Shell extension that displays a stock price in the top bar. Its functionality works, but is currently very limited until a preferences pane gets built.
Currently, all it does is display PayPal's stock price, refreshed hourly, from Alpha Vantage. Ideally, all three of those things would be configurable.
This extension was built with GNOME Shell 3.34.1 on openSUSE Tumbleweed.