How to understand these VIXY moves?

I am relatively new to VIX and its ETFs. But as far as I know VIXY tracks the S&P 500 VIX Short-Term Futures Index, and when S&P 500 shows more volatility, VIXY would move more. But in the recent days it doesn’t show this character or even show the opposite (please see the attached chart and the notes).

What are the recent VIXY moves implying?

 

I traded the VXX on Friday and noticed it closing at highs on Thursday. This is a great blog to follow to understand VIXY, TVIX, and VXX a bit better. This guy knows his shit.

http://vixandmore.blogspot.com/

 

Thanks for the link. There are some good articles there.

But so far it seems to me that VIX or VXX etc. are often moved by expectation or the supply/demand of the ETFs, rather than following the SPX volatility formula. Or say they follow SPX volatility formula only some of the time

 

They don't follow the spot VIX, they follow the 1m VIX futures - so they will not follow the VIX. They also suffer/profit from contango/backwardation from time to time.

 

And to make it more confusing, the VIX futures (that drive the VXX) don't settle on an underlying calc'd the same way as the spot VIX you see quoted. Generally the same, but enough differences that you can see the two not converge at expiration.

 

3/19 is another obvious example, VXX down $1.30 but TVIX up $0.26 (they also moved in different directions the day before ). I guess VXX TVIX VIX should be treated as different animals. They may move in different directions whenever they want and don't have to follow the rule?

How do you understand this

 

http://vixandmore.blogspot.com/

see wed march 7th postings for why tvix is all screwed up

 

Thank you for the link. But too bad I have no access to that website from my area right now(I'm traveling). I'll take a look after the trip.

 

no problem my friend.

IMHO I'd stay away from tvix like the plague it's a broken instrument not acting like it's stated purpose.

 

Thanks for the article! Now I've got some basic idea why TVIX behaves strangely. I will stay away from TVIX for now. It seems the VIX and its related products are quite complicated, I guess more careful TA is also needed when trading them.