Whilst the headline VIX saw a net weekly decline, the 2x lev' bullish instruments of TVIX and UVXY held broadly flat, with net weekly declines of -4.6% and -1.5% respectively. Once the fed is out of the way, equities will likely resume higher, and that would seem VIX - and the related instruments, rapidly decaying once more.
First, an update on the VIX, which saw a net weekly decline of -12.2%.
As for TVIX and UVXY, all things considered, they held together relatively well. This is no doubt because of the genuine uncertainly about next week's Fed decision.
Once that is out of the way... assuming no rate change, the VIX will be crushed sub-teens, and that will see considerable decay in TVIX/UVXY.. and even VXX.
Yours truly remains holding the view that the VIX-long trade is dead. That view only changes if the market declines to the sp'2050s or lower.