How do I refresh the graph in the iOS 9 Stocks app? In the Stock app, when I click on a ticker and select "1W" to specify one week's worth of stock data on the graph, it pulls the data and displays the graph.

If I go back many hours later, the graph shows the cached version of the graph.

Is there a way to get the app to update the graph?  The only way I know is to close the app and re-open it.
It seams like the only option is closing the app via multitasking and reopening it again.

A "swipe down to refresh" function could be useful to have in this case.