There are already VIX for 9 days (VIX9D), 3 mo (VIX3M), 6 mo (VIX6M), 1 yr (VIX1Y).
Just as the regular VIX (for 30 days) uses SP500 options that bracket 30 days +/- 7 days, VIX9D brackets 9 days options (unclear by how many days +/-).
These symbols are also recognized by Yahoo Finance as ^VIX9D (with very limited History), etc, but not by StockCharts (only $VIX is recognized among these). Both have quite a bit of History for regular ^VIX or $VIX.
Yahoo Charts for 1 mo for ^VIX and ^VIX9D look similar although ^VIX9D values are slightly higher. For ^VIX9D, the Yahoo Summary page chart is good for 1D, 5D, 1M, YTD, but nothing else. The Yahoo Chart and History tabs doesn't pull any data.
My guess is that CBOE is looking into even shorter-term VIXnD whose brackets may include 0DTE.
VIX9D
https://www.cboe.com/us/indices/dashboard/vix9d/
https://finance.yahoo.com/quote/^VIX9D?p=^VIX9D&.tsrc=fin-srch

They forgot "No K-1"

https://www.sec.gov/Archives/edgar/data/1618627/000089418923001074/rbb-497e.htm
THE RBB FUND TRUST
Element EV, Solar & Battery Materials (Lithium, Nickel, Copper, Cobalt) Futures Strategy ETF
(the “Fund”)
(Ticker: CHRG)
______________________________________________________________________
Supplement dated February 10, 2023
to the Prospectus and Statement of Additional Information (“SAI”)
each dated December 28, 2022, as supplemented
______________________________________________________________________
This supplement serves as notification of, and provides information regarding, certain changes to the Fund effective as of February 3, 2023. As a result, the following references in the Prospectus and SAI should be updated accordingly.
1. Change in the Name of the Fund
The name of the Fund is being changed to the following:
The Energy & Minerals Group EV, Solar & Battery Materials (Lithium, Nickel, Copper, Cobalt) Futures Strategy ETF
2. Change in the Name of the Investment Adviser
The investment adviser to the Fund has changed its name from Element ETFs, LLC to The Energy & Minerals Group Advisors, LLC. There have been no changes to the ownership or control persons of the Fund’s investment adviser.
3. Change in the Website
The Fund’s website has been changed from www.elementfunds.com to www.emgadvisors.com.
Investors should retain this supplement for future reference.

Article has a Good explanation of 0DTE; there are 1DTE,..., NDTE, etc too. There is nothing new here as all options near expiry will go through these phases. But no-commission trading makes this trading possible for retail (in the old days, $5-10 commissions per options contract (100 shares) didn't make this worthwhile except for dealers).
Concern is that this options activity is outside of formal measurements like VIX that are options-based but use options with 30 +/- 7 days left to maturity. I suppose new real-time options measurements may develop to capture NDTE in future, but all we can do for now is watch their huge volumes.
Forsyth in last week's Barron's also had a warning on them.

0DTE - “Zero Days to Expiration (0DTE) Options and How They Work”
ARTICLE - How "0DTE" Options Will Cause the Next Black Monday

+1.
Still learning! Thanks.

@yogibearbull - Thank you for the correction. You are correct that the term flash-crash doesn’t fit what happened in October ‘87. I’ve attached an excerpt from Investopedia that more correctly defines flash-crash. I continue to learn so much here.
All I remember is I was driving home from work late in the afternoon when they interrupted the music on the radio to explain what had happened in the markets. Stunning. Lots of grim faces at work the next morning from those nearing retirement who had a lot more invested than I did at the time.
”The term flash crash refers to an event in the electronic securities markets wherein stock withdrawal orders rapidly amplify price declines before quickly recovering. The result of a flash crash appears to be a rapid sell-off of securities that can happen over a few minutes, resulting in dramatic declines. But as prices by the end of the day, it's as if the flash crash never happened”
Above excerpt from Investopedia (“Flash-crash” definition)
Here’s the earlier cited Wikipedia Article on the Crash of 1987

I haven't done full research on it (yet), but I don't think that the term flash-crash or mini-crash was around in 1987. These last from minutes to hours on a single-day. The Big one was in May 2010 and there were several subsequently too. Then, the WSJ mentioned in 2010 that May 1962 may also have been a flash-crash (that was at the tail end of 6-mo decline in 1962/H1). They are stop-loss order killers (many such orders were canceled that one time in May 2010, but not later).
Anyway, 1987 was a genuine historic crash. Market had peaked in August 1987, the historic crash of -22.6% was on October 19, 1987 (the Wall Street Week video above was from October 16, 1987), and turnaround began in December 1987. So, not only there was a record 1-day decline, but the decline lasted from August-December, 1987.
There were investigations in 2010 on what had caused that flash/mini-crash; there were several subsequent flash/crash too. New exchange rules came into force. However, there wasn't any good explanation. The best I saw was that the HFTs and unlinked cross-markets (stock exchanges were closed but futures exchanges remained open) caused market instability.

“I've had to cancel a small exchange between funds, 2 days in a row… “
Goodness. I must confess to cancelling a small sell order myself on one of my funds at Fido about 10 minutes before today’s close. Great minds think alike.

Good thoughts from @catch22. Generally people’s time horizon seems to have grown shorter in recent years. We live in an age of “instant everything.” There’s a lot in Barron’s this week about the frenzied buying and selling of ”end-of-day options” by both professional traders and individuals alike. In effect, plunk some $$ down on a speculative bet (going either long or short) at 9:30 AM and than “cash-out” the same afternoon. One market observor predicted this craze might even lead to a *“flash-crash”. It’s definitely contributing to the greater volatility. ISTM I read that last Friday was the single largest options trading day in history. Perhaps @Crash is seeking conviction where there is none - or precious little.
It is also possible the increased volatility is a precursor to a large move either up or down. If markets were to drop sharply, I know more than one prognosticator who will get caught flat-footed. There’s actually quite a bit of bullish sentiment out there as I think some numbers posted by @yogibearbull earlier today substantiate.
Here’s Marty Zweig calling the October 1987 *flash crash. The Monday following the show, the Dow fell 22.6% - most of that in just a few hours late in the day. Advance video to the 6:30 mark where Zweig is introduced.

Here’s a Wikipedia Article on the Flash Crash of 1987

@Crash
One supposes there is a math formula regarding 'conviction' in the investing arena.
Compounding via time is good one, eh? The very meaning of the word.
So, one's conviction should be time based. A day trader conviction period is obviously short; but may provide a decent daily compounding if they are good at what they do. OR NOT !
The investment market players have their convictions, too; but they may not always be what the individual investor is hoping, for direction.
Fidelity indicates that their FBALX (inception1986) has a full life return, which includes distributions; is at 9.2%. In this time frame, one will find numerous points where it would have been difficult to maintain a 'conviction'.....but, the return is there regardless of the chart patterns.
Once one has determined their investment compounding time frame; investing life may become easier to deal with, yes?; and not be overly concerned with an open/close period for one day. Yes, I watch, too.

SP500 4,100 was an important level. Market has to be comfortable there, and so far in Feb, all closings have been above 4,100 (although it has been breached intraday). Then, the next hill is at 4,325.
You may have seen nearby that the AAII Bull-Bear Spread has turned positive after a negative streak of record 44 weeks. Some fireworks are already being seen in trashy stocks. Golden-cross also happened in Feb.
https://stockcharts.com/h-sc/ui?s=$SPX&p=D&yr=1&mn=0&dy=0&id=p51599677386

Powell has said that he watches 3m-18m spread (close is readily available 3m-2y spread) & those have been clearly inverted since December 2022.
https://stockcharts.com/h-sc/ui?s=$UST2Y-$UST3M&p=D&yr=1&mn=0&dy=0&id=p09344239375

@day1queen Hi, I have just emailed you if you will please email me and let me know about your situation. Thank you, Teresa

@Mav123 Hi, I have just emailed you if you will please email me and let me know about your situation. Thank you, Teresa

Not a market call on my part. Karniol-Tambour (video) is looking out months - or even years. So I don’t feel she’s necessarily making a market call either. But I do think her longer term outlook is supported by the increasingly strident interest rate talk coming from various Fed officials this week plus recent / continuing movements in the bond market. The spread between 2 and 10 year Treasury bond as of this morning is the most inverted since the early 1980s with the 2 year Treasury yielding 85 b/p more than the 10-year . A steep inversion has often in the past been a good indicator of approaching recessions. (Just because I’m paranoid doesn't mean there won’t be one … )
Karniol-Tambour is the newest member of Bridgewater’s 3-person investment team. She does not (to my recollection) address the inverted curve.

https://www.yahoo.com/now/worlds-largest-hedge-fund-founder-180310822.html
I found this opinion interesting in the context of our discussions in and around TIPS. Basically, if you take all the bs out of crypto and coin and what not, Dalio is suggesting a future where we hold cash indexed to inflation. TIPS are just that minus the cash in the bank part. TIPS Bond holders get inflation + real yields. If one likes inflation linked cash, that means Real Yield = zero. Right now TIPS offers Real Yields of +1.4-1.7% depending on the maturity. This is part of the reason I am leaning into TIPS. As @yogibearbull has often written, he prefers 5 year TIPS. There too one gets 1.4% Real yield and much less duration than the 30 year TIPS which makes the 5-year bonds less volatile.
In any case, increasingly I feel the inflation priced into the bond market of around 2.25% and the inflation I feel all around me are such different things. I don't quite know what's a good answer to the problem except holding a healthy amount of TIPS. Of course if you hold stocks for the very very long run, eventually the earnings and dividends are in excess of whatever yields tips will generate.

For the week ending on 2/8/23, bullish became the top sentiment (37.5%; average) & bearish remained the bottom sentiment (25.0%; below average); neutral became the middle sentiment (37.5%; above average & tie); Bull-Bear Spread was +12.5% (!; below average). Investor concerns: Inflation (moderating but high); economy; the Fed; dollar; crypto ice-age; market volatility (VIX, VXN, MOVE); Russia-Ukraine war (50+ weeks); geopolitical. For the Survey week (Th-Wed), stocks were mixed, bonds down, oil up, gold down, dollar up. Bull-Bear spread became positive for the first time since 3/31/22 (the negative run was for a record 44 weeks). #AAII #Sentiment #Markets
https://ybbpersonalfinance.proboards.com/thread/141/aaii-sentiment-survey-weekly?page=9&scrollTo=924

TIAA annuities within 403b are low-cost. For example, CREF Stock VA has all-in ER of 0.23% only (AUM $112 billion). Post-retirement, money can remain as-is in TIAA Traditional (like SV; current crediting rate 6.00%) and TIAA and CREF VAs, but can also be rolled into IRAs.
CREF Stock VA https://www.tiaa.org/public/investment-performance/investment/profile?ticker=268555492
TIAA Traditional - RA https://www.tiaa.org/public/investment-performance/investment/profile?ticker=47933630
There is discussion on Secure 2.0 implications at the thread below at the M* TIAA Forum. When one annuitizes from TIAA 403b, TIAA issues a separate contract for it and it isn't clear whether the money is still part of the original 403b contract (it should be, IMO). My guess is that TIAA may modify its setup to benefit from Secure 2.0; the language is very specific on split annuitized-unannuitized $s within the same account. Beware that early discussion on this M* thread was based on some erroneous info provided by Fidelity at its website; I contacted Fidelity and was informed that the info at Fidelity website has been corrected.
https://community.morningstar.com/s/question/0D53o00006OFGTRCA5/update-on-secure-act-of-2022