RPS scan (Relative Price Strength)

Since this is not a built-in study that comes with Thinkorswim you will need to provide the exact specifications used to compute the value for Relative Price Strength.

I see that you have posted this in the Stock Scanners topic. But you have requested a watchlist that sorts the stocks, ranked by RPS. A stock scanner only returns a list of stocks meeting specific criteria. A stock scanner cannot sort results. So you will need to explain how the scan is to select the list of stocks. That will be one part of the solution. The second part of the solution will be the code that displays the Relative Price Strength value in a watchlist. Which will then allow you to sort by that column. So please be careful about your use of these terms. Stock Scanner is completely different tool that Watchlist.

I will also add that if your computation involves comparing the price of all stocks to one another, this is impossible to do in Thinkorswim. You can compare the price of a group of stocks to a single stock. But you cannot compute values that represent how each of those stocks are related to one another in regard to price performance.