This can be a simple unordered list.
You can use any charting library. The example uses Google Charts. Display the prices in a suitable chart format.
You can use any real-time stock reporting API. The example uses IEX. There are several free stock market APIs to choose from ( Finnhub.io, Tiingo, Alpha Vantage ). Read the documentation and figure out the most efficient way to access stock data for multiple stocks.
Update prices every 5 seconds in the chart. Remember that the stock market operates only at certain times of the day and is closed on holidays. The real-time update should be clearly visible so display the price on the chart (see screencast).
Your submission does not need to be an exact visual match to the example. We are looking for functionality and coding skills. Take some creative license to showcase your skills if you want but minimalism and coding elegance is primary.
The easiest option would be to develop this as a SPA using HTML and Javascript (example used less than 10 lines of HTML, less than 50 lines of Javascript and no custom CSS). Use jsFiddle, JS Bin or other suitable environment to build and submit.
Use any external libraries that you require.
You are free to implement this using other technologies that you are familiar with, including server-side. Please send your code with the submission if you take this route but you should deploy the live app to a cloud environment and submit a URL as we will not be building and running your code.