Track stocks on Apple Watch
Use the Stocks app 
on Apple Watch to see info on the stocks you follow on your iPhone. See iPhone User Guide for more information about using the Stocks app on your iPhone.
Ask Siri. Say something like: “What was today’s closing price for Apple stock?”
Add and remove stocks
Your Apple Watch displays the stocks found in the Stocks app on your iPhone, but you can add and remove stocks right on your Apple Watch. Just open the Stocks app on your Apple Watch to:
Add a stock: Scroll to the bottom of the screen, then tap Add Stock. Say the name of the stock, then tap Done. Tap the name of the stock in the list.
Remove a stock: Tap the stock you want to remove, firmly press the display, then tap Remove.
To reorder stocks on your Apple Watch, open the Stocks app on your iPhone and reorder them. The order changes on your Apple Watch to match.
See stock data on Apple Watch
Open the Stocks app
on your Apple Watch.Tap a stock in the list.
Tap < in the top-left corner to return to the stocks list, or turn the Digital Crown to scroll to the next stock in the list.
Choose the data you see
Open the Stocks app
on your Apple Watch.While viewing the stocks list, firmly press the display, then tap Points, Market Cap, or Percentage.
Tip: You can also open the Stocks app on your iPhone, then tap the price change for any stock to see percentage change or market cap.
Switch to Stocks on iPhone
Open the Stocks app
on your Apple Watch.On your iPhone, double-click the Home button to show the App Switcher. (On iPhone X and later, swipe up from the bottom edge and pause to show the App Switcher.)
Tap the button that appears at the bottom of the screen to open Stocks.