If you hear a reference to a “Smoothed 50” line in the trading room, it’s referring to a 50 EMA of a 50 EMA. That is, a 50 Exponential Moving Average of a 50 Exponential Moving Average. It appears as a moving average on the charts. It's often added as a dashed magenta line.
Getting this on your chart varies by platform. In NinjaTrader 7 or 8, you can add this without requiring an indicator. The method for doing this is explained in the Renko setup videos (search this knowledge base for ninjatrader renko charts to get the link to the video that explains it).
On non-NT platforms, you’ll likely need an indicator to draw the Smoothed 50. This is not something that BCT provides for all platforms, but it can often be readily found in other code repositories on the web. Asking other traders in slack chat might point you to a source for this indicator if it can’t be easily found.
This indicator is sometimes known as a Double Exponential Moving average, or DEMA. You can download the TradeStation version of a DEMA indicator HERE (sorry only for TradeStation).
See this link for more information about the EMAs used on our Renko charts, as well as a video on how to set up the Smoothed 50 in Ninja Trader.