I ran TVIX through the PriceDelta tool, it told me the best way to trade it since Dec 2010 (at least using the methods in the PriceDelta universe), was
Buy signal if price is 1.9% above the last close.
Sell signal if price is 1.9% below the last close.
If buy and sell signals occur on the same day, ignore them, otherwise trade at the next open.
Returns were 345%, 724% and 3572% for Long, Short and SAR respectively (Dec 1 until Aug 23rd).
Since TVIX is in a hold state and there was both a buy and sell signal today (Aug 23rd), it remains in a hold state.