Robert,
This issue will ever be recurring and I repeat that I am against providing indicative limits and stops for related ETFs!
These are kindly provided by Pascal based on the volatility correlation between the instruments. With the way triple leverage ETFs are adjusting daily with a decay or compounding factor, it is normal that their volatility is varying daily from the correlation with IWM. The actual stop is not changed. If IWM stop is hit, you get out of TNA whatever the indicative TNA stop. Period.
Billy