SPD is one of the new Simplify ETFs with complicated strategies. The web page has little information but the theory should work and is very quantitatively documented. I have not tried calling them to get a little better description of potential ups an downs (Barrons ( Sept 6 2021) said SPD's "protection would be minimal until there is a selloff of 30 to 40% " although the author had no data to back her up. It depends on the structure of the puts which also change as they get closer to exploration.
Unfortunately it is hard to find specific goals in any of the material from these funds. TAIL has been running for several years, but there is little description of what to expect
The "Buffered ETFs " seem to be more specific, as they have a specific month in their name and focus on the next 12 months.
IT taks a lot of work to sort these things out

Much more information on PFIX is available from it's creator, Harvery Bassman, whose commentaries and musings on interest rates, money creation and the economy are really worth reading in detail.
https://www.convexitymaven.com/
He has a very entertaining and very wise blog. While the math and options talk is heavy, I think he is brilliant and clearly knows what he is talking about.
He recently joined Simplify Asset Management to mange ETFs designed to do things for individual investors that are hard to do otherwise ( Puts, call, swaps, convexity strategies etc)
Unlike a lot of public bears I think Bassman knows what he is talking about and backs it up with math and data
He explains the rational for PFIX in his May 2021 commentary "Helicopter Defense"
https://www.convexitymaven.com/wp-content/uploads/2021/05/Convexity_Maven_-_The_Helicopter_Defense.pdf
and likens it to fire insurance. It is basically a swap on interest rate futures that will soar ( will quadruple ) if rates hit 4% by 2024 or so. Backed by T bills as collateral, it can loose no more than 50%
He recommends using a chunk to prevent your bond funds from taking you to the cleaners, or to protect yourself against other disastrous outcome in store in if inflation takes off and you have an adjustable rate mortgage for example.
He has tables that provide examples of how much to invest etc.

Relative performance of FDIC cash looking good as well so far this year.
Astounds me in my humble, no nothing opinion what appears to be why so many are in a hurry to jump back in looking for a bargain....this might have a bigly ways to go on the downside.
Remember back in 87, Black Monday? Guys who were my age back then in the office saying there goes my retirment...remember March 20'....guys looking shell shocked...remember 01, the jig jag downwards, down several points, up a few, down several...
Don't we all really know this is an artificial, juiced, BS of a market I mean casino?
Let it flush, let it flush bigly. Hit the freaking reset button already. Make asset prices reflect reality and let the older folks gain a little interest over infaltion on their money market accounts.
Enough with this BS already.
Do what you want, be careful and good luck to ALL,
Baseball Fan

+1 @hank. The main reason I'd stay with TRP is my big chunk in PRWCX. I'd be unable to get back in, of course. Until it opens again to new investors. But I've certainly already "made my money" in that fund..... It's not a small decision, to fully exit a fund house. But of course, I don't want to let simple INERTIA stop me from doing what's best for ME. "Fidelity is a dream." I could go in person to talk to someone over there, here in town. I could ask my questions. Once the account is set-up online, I'd be free to get into and out of a bunch of mutual funds from a bunch of different Houses--- even in a T-IRA, yes? Thank you.
(*Added: ork! No Fidelity office here. I suppose I'll call them. )

+1

BTW, the site you quote shows wrong denominator for Macaulay Duration - it should the the sum of the [present values of] cash flows (not the bond price),
In an efficient market, that is the price. If you prefer, we can call that the "correct" price rather than the "market" price. See, e.g. Investopedia, where the denominator is stated to be:
"Current Bond Price = present value of cash flows"
https://www.investopedia.com/terms/m/macaulayduration.asp
[Wiki and Investopedia, IMHO not two of the highest quality references.]
the weighting [of the amount of time to each cash flow] is indeed by the present values of cash flows
Σ ti x PVi
This is the same as the weighting of cash flow PVs by time to each flow.
Certainly there are finance books that describe the expression as you've stated it. Just as other finance sources describe it the other way. FTSE Russell for example, says that "The Macaulay duration of a bond is the time weighted average of the remaining cashflows". (See Section 3.3 here.)

When I calculate the center of mass, I take each bag (cash flow PV) and weight it by its position (time). You may chose to calculate center of mass differently: by taking each position on the seesaw and weighting it by the size of the bag at that location.
Either way, the result is the same.
And yes, we (or at least I) have likely thoroughly confused the OP. In my defense, I chose to blame that on the complexity of the subject. :-)

Hank
I don't follow u comment.
Personally I consider ~10% corrections as garden variety and am not interested in a hedge against those. It's bigger ones that I would like to hedge against and SPD is designed for bigger drops.
SPD is also designed to automatically monetize the puts and purchase equity automatically after drops so this takes me out of the decision making which is what I want. SPD is relatively young and so may fall flat in practice but theoretically it is doing what I am looking for. I.e. An ongoing put(2%) within the context of an equity(98%) fund and all rules based and automated.

Howdy folks,
@hank you may be correct about the precious metals. I'm copying from Liberty Coin Service's Patrick Heller's FB page with YTD returns.
Patrick Heller "Current financial markets are getting interesting. Here are how prices have changed from the close on December 31, 2021 through today, January 20, 2022:
Platinum: +8.9%
Palladium: +8.5%
Silver: +5.9%
Gold: +0.8%
US Dollar Index: -0.2%
Dow Jones Industrial Average: -4.5%
Standard & Poors 500 Index: -5.9%
Bitcoin: -9.0%
NASDAQ: -9.5%
Russell 2000: -10.0%
As you can see, the prices of platinum, palladium, and silver have outperformed gold thus far in 2022. Gold has outperformed all the other assets listed through the first 20 days of this year.
By the way, the US Treasury 10 Year Note interest rate has jumped from 1.52% to 1.83%, an increase of 20.4%!"
and so it goes,
peace and wear the damn mask,
rono

Hopefully, you have access to this Bloomberg article.
$3.3 trillion stock options expiry

2022 better not turn out to be Death by 1,000 Cuts. Can't we just get a few big wash out days where equities are down -4% or -5% per session? That's the way to do it.
This correction is too orderly.

(Macaulay) duration is the time weighted sum of cash flow present values normalized by dividing by the bond price.

https://www.fincash.com/l/basic/macaulay-duration
What you were using was modified duration (or effective duration), i.e. sensitivity to interest rates:
TIPS have higher durations than Treasuries of comparable maturities, so they are hit worse from rising rates.
Modified duration is the derivative of present value (PV) with respect to rates (again, normalized by dividing by bond price, i.e. PV). That turns out to be Macaulay duration divided by (1+r) where r is the discount rate per coupon period.
This is easy to see. Start with the PV formula:

After dividing by the bond price, differentiating with respect to i (rate) gives:
{[(-1 x PMT1/(1+i)¹) + (-2 x PMT2 /(1+i)²) + ...)] / BondPrice} / (1 + i) =
- ( timeWeightedCashFlowPVs / BondPrice ) / (1+i)
- MacaulayDuration / (1 + i)
Related to, but not the same thing as Macaulay duration.
Still, that doesn't address your more significant assertion that TIPS' duration (whatever the form) is longer because cash isn't paid out until maturity. IOW, that TIPS are effectively zero coupon bonds.
With a traditional CD, interest compounds at a fixed rate. So calculating APY and YTM is easy. In fact, all that really matters (except for tax purposes) is the final value of that CD. You could call it a zero since you don't get the cash flows until maturity.
Still, there are interest payments; you can see it in the balance reported for your CD. The risk with fixed rate CDs (as with zero coupon bonds) is that interest rates may rise and you can't deposit those interest payments at the new higher rates.
If the bank did allow you to draw the interest payments and redeposit them at higher rates, that CD would be more valuable to you. It's not that you're literally getting your hands on the cash, it's that you're able to get current (higher) market rates on the interest as it is credited.
Same with TIPS. You don't get your hands on the inflation adjustments. But you see them in your balance (i.e. "principal amount"). And if inflation rates go up, that new balance benefits from the higher rates.
In this regard, TIPS work even better than redepositing the CD interest or reinvesting bond coupon payments. With the CD or the fixed rate coupon bond, only the interest payments receive higher rates going forward. With the TIPS, the original principal (as well as the inflation "adjustments") receive the benefit of higher rates.
With respect to inflation, TIPS are floating rate bonds, and as such have zero duration.
I started with the statement: "The relationship between inflation adjusted (real) durations and nominal durations is somewhat complex." This may help (or further confuse):

Nominal bonds are generally considered to have one duration (the sensitivity of the bond's price to a change in its nominal yield or interest rate), but inflation-indexed bonds, such as Treasury Inflation-Indexed Securities (formerly, Treasury Inflation-Protected Securities, TIPS), may be regarded as having two durations: Di, the sensitivity of the bond's price to a change in inflation, and Dr, the sensitivity of the bond's price to a change in real interest rates.
For a nominal bond, whether a change in yield was caused by a change in inflation expectations or a change in the real interest rate does not matter; the effect on the bond's price is essentially the same either way. But for a TIPS bond, an increase in inflation does not affect the bond's price because the change in the cash flows in the numerator (of the equation for discounted cash flow analysis) is indexed to inflation and the discount rate in the denominator has also been increased by the same change in the expected inflation rate. Thus, the TIPS bond has an "inflation duration" of zero. A change in real interest rates, however, affects the price of a TIPS bond much as it does the price of a nominal bond, so a long-term TIPS bond has a long real-interest-rate duration—say, 15 years.

https://www.tandfonline.com/doi/abs/10.2469/faj.v60.n5.2656
That is why Vanguard moved to short term TIPS.

I just checked at M* the valuation of top 10 components of ARKK portfolio. Two companies are rated four stars (Twilio & Zoom), one company is rated five star (Teladoc), and one company is rated two stars (Tesla). All other companies are rated 3 stars. The higher the star rating the more undervalued a company is. Assuming M* valuation work can be relied upon and assuming the market pays attention to M* work, it appears ARKK may currently be in the range of fair value. But given market's mood always swings too far from the median, another 15% drop in ARKK from today's close price would put it at $64.50, which I think is a good entry point.

+1 Berlin Germany residents voted for expropriation of thousands of apartments owned by big developers, but that process hasn't been completed yet.

Except:
“Cincinnati government entity outbid more than a dozen investment firms to buy 194 homes in and around the city, a move meant to keep tenants in their homes and private investors out of their neighborhoods. The Port of Greater Cincinnati Development Authority agreed last month to pay $14.5 million for the properties scattered throughout Hamilton County, which includes Cincinnati. While continuing to operate them as rentals, the agency said it intends to upgrade and eventually sell the homes to their primarily low-to-middle-income tenants …
“The program is the most aggressive response yet by local officials looking to keep homes out of the hands of professional investors. Publicly traded companies, private-equity firms and thousands of smaller investors have been buying up single-family homes and renting them out, usually to people who can’t afford the steep down payments. Laura Brunner, CEO of the Port of Greater Cincinnati Development Authority, worries that a rental-industry ‘feeding frenzy’could lock families out of homeownership. Investors now account for about 18% of all U.S. home sales, up from about 8% in 2009 …”
The Wall Street Journal - January 19, 2022
Story By: Konrad Putzier and Will Parker

Well I was at the gym today but didn’t see nobody naked. Got the ol ticker up to 120 BPM on a treadmill and it didn’t break. Thanks for sharing Catch.
Henry David Thoreau - “Time is but the stream I go a fishing in.”

@hank
IG bonds today and IG bond futures at this time have assumed a more normal relationship to equity weakness. Some relief in the bond sell down is in place at this time (Jan. 20, 10:30 pm, EST).

Hi @Old_Joe
Heard part of a short blip today about ASML also having problems obtaining parts/product for their factory in Berlin, after the fire there, a few weeks ago. Overall, I believe they remain well positioned in this tech. area.
ASML articles
Take care,
Catch

Following up on yogibearbull's post above, this video was referenced by that M*post:
It shows a zero visibility automated landing at the Milan International airport, and it's well worth a watch. At the beginning it seems as if there's no motion at all... be patient.

If you happened to be flying on this aircraft would you be concerned that the radio altimeters were working correctly?