javafx: How to stop an object's background task running when the object itself is deleted from Observable List?

I have a Trade object and whenever it is constructed, it kicks off a task in the background (i.e. say download currentPrice) and start running every 10 seconds.

When the Trade object is created, it is also added to a ObservableList .

Problem: When I delete the object from the ObservableList, I can see that the task (download currentPrice) is still running in the background, although the object is not in the ObservableList anymore.

1. Is the object actually deleted ?
2. How can I stop the object's background task from running when the object itself is already removed from the ObservableList?

My goal is to delete the object forever and stop its background task from running as well.

public class Trade{

....

private final ScheduledService<Number> priceService = new ScheduledService<Number>() {
        @Override
        public Task<Number> createTask(){
            return new Task<Number>() {
                @Override
                public Number call() throws InterruptedException, IOException {
                    return getCurrentPriceFromGoogleFinance();
                }
            };
        }
    };

    public Trade(){
        priceService.setPeriod(Duration.seconds(10));
        priceService.setOnFailed(e -> priceService.getException().printStackTrace());
        this.currentPrice = new ReadOnlyDoubleWrapper(0);
        this.currentPrice.bind(priceService.lastValueProperty());
        startMonitoring();
    }


     public ReadOnlyDoubleProperty currentPriceProperty(){
         return this.currentPrice.getReadOnlyProperty();
     }

     public final double getCurrentPrice(){
         return currentPriceProperty().get();
     }

     // multi-threading
     public final void startMonitoring() {
         priceService.restart();
     }

     public final void stopMonitoring() {
         priceService.cancel();
     }

     ....
}