Please follow the instruction:

- Tap Edit above the list of stocks

- you will see two tabs in the bottom: "Custom order" and "Sort by symbol"

If you choose the "Custom order" tab it allows you to reorder your positions manually. Press and hold the 'three lines' icon to the right of the stock symbol you wish to move, then drag and drop it to the position you like.

If you choose the "Sort by symbol" tab stocks will be displayed alphabetically.