NinjaTrader does not support this natively but there may be 3rd party add on available, you can search at www.ninjatraderecosystem.com.
I really don´t understand why it´s still not possible to get the percent change of each stock with NT 8. You can get this with tos, tc 2000, tradingview. This would really help much.
Truth be told - there's a lot of basic stuff NT 8 does not provide. Instead of suggesting 3rd party add-ons - I think NT should implement these things themselves. I've coded various basic stuff in NT8 myself as it's simply not offered in NT.
There's a lot of free stuff available. I've also hired people on UpWork to do basic stuff. Usually, you can get an indicator done for 50-100 bucks. Still, I think Ninjatrader should supply these basic indicators such as % change. I believe they have a % change indicator, BUT, they calculate it based on a different closing price than what I have on my charts. So, essentially it's meaningless and flat out wrong.