Thornburg describes TSUMX newer (3/1/19- ; AUM $70 million only ) as multi-asset fund (stocks, bonds, alternatives) that is "unconstrained" or go-anywhere. No ranges for assets are specified in the prospectus but M* puts it in conservative-allocation/30-50% equity based on its current positioning. It may be a milder version of Thornburg's world-allocation/multi-asset TIBAX (NTF/no-load at Fido and Schwab) and its newer type of CEF TBLD (term-structure; not leveraged for now). TSUMX has transaction-fees at Fido and Schwab and both have lower min for IRAs (Fido $2,500; Schwab $1,000). I am surprised that Thornburg hasn't made it available as NTF/no-load at Fido and Schwab.

According to the account disclosure, cash gets FDIC coverage when it is swept into Happy State Bank, which happens on a daily basis:

you authorize and direct GoldStar Trust Company (“GoldStar”) to deposit any uninvested cash held in your IRA/ESA into an omnibus demand deposit account maintained by Happy State Bank, an affiliate of GoldStar (the “Deposit Account”). On a daily basis, any cash in your IRA/ESA, for which GoldStar has not received an investment or other direction as to its disposition, will be deposited into the Deposit Account. Such uninvested cash will remain in the Deposit Account until you direct GoldStar as to the investment or other disposition of such uninvested cash, and such direction is implemented. The Deposit Account is insured by the Federal Deposit Insurance Corporation (“FDIC”)), up to the maximum amount per depositor, which is currently $250,000.

https://www.goldstartrust.com/PDFforms/Traditional_IRA_Simplifier.pdf
One wonders a bit about the choice of the term "affiliate". "Affiliated companies are companies that are related through ownership, either with one owning the other as a minority shareholder or with multiple companies being owned by a third party." Is Goldstar Trust a subsidiary of Happy State Bank as you write, or merely an affiliate? Merrill is an affiliate of Bank of America, it has FDIC-insured sweep accounts, but it doesn't say that cash is insured before it is swept into the bank.
https://corporatefinanceinstitute.com/resources/knowledge/strategy/affiliated-companies/

Thanks @Davep.
Just adding what I learned if it is helpful to others.
It is a multi-asset, real return fund. Its current bond allocation is mostly investment grade with a big slug of US Treasuries.
https://www.thornburg.com/wp-content/uploads/home/pdfs/TH4795_C-fact-sheet-S.pdf.pdf
If one overlooks the idiosyncratic rise and fall of NAV in February 2021, it compares with and might even have a slight edge over FMSDX (depending on one's temperament).
If I was not averse at this point to adding an additional fund to my portfolio, I would seriously consider this.

@Derf -- I don't know what OT stands for
@msf -- I don't think the vulnerability window you called out for fintechs is applicable to Goldstar Trust. Goldstar Trust is a subsidiary of a bank that has FDIC protection. I see the below statement as cash being protected because the uninvested cash of a Goldstar Trust customer is sitting in the parent company(Happy State Bank) account. There isn't any uninsured fintech middleman between the consumer and Goldstar/Happy State Bank
FDIC NOTICE: IRA and/or Bond investments represented on this website are not FDIC-insured, are not guaranteed by GoldStar Trust Company, and involve risk including possible loss of principal. If held in a GoldStar IRA or GAMMA account, the un-invested cash portion is FDIC insured up to $250,000.

It's hard to think of this as a mutual fund when 50% is in one stock. The other issue I could image is the potential tax liability if the fund starts experiencing redemptions and the manager has to sell appreciated stock. Given that, if one is a Tesla fan, why not just buy Tesla directly? According to the fund's June 30, 2021 semiannual report--https://sec.gov/Archives/edgar/data/1217673/000119312521257076/d171358dncsrs.htm#cov171358_33--the fund had $5.6 billion of unrealized capital gains in its $6.9 billion portfolio. One could easily imagine the fund distributing some hefty taxable distributions if some of those unrealized gains have to be realized because of shareholders selling the fund.

As with fintechs, there's a window between the time cash goes into the account and it is swept into an insured bank when it is not insured.
For example, here's a long piece from DepositAccounts.com quoting WealthFront:

While funds are at Wealthfront, before they are swept to the program banks, they are subject to SIPC’s protection limit of $250,000 for cash

https://www.depositaccounts.com/blog/banking-fintechs-safety-money.html
The risk of assets being stolen from a brokerage are quite remote. Would you use a brokerage without SIPC insurance? The other risks in the article are entirely under your control; the risk of assets being stolen out of an account are not.

The SEC has rules for diversified vs nondiversified funds. BPTRX is nondiversified.
In the 1940 Act, Congress defined a nondiversified fund simply as one that didn't meet the requirements to be called diversified. Just a basic partitioning of the fund universe into two parts.
https://www.law.cornell.edu/uscode/text/15/80a-5
What @sma3 might be thinking of is not a section of the 1940 Act (under which investment companies are registered), but rather 26 U.S. Code § 851 that defines regulated investment companies. That's a more expansive category that includes 1940 Act registered investment companies and also some common trusts that do not fit the definition of an investment company.
In any case, this statute requires that with respect to half (50%) of the fund's assets, the fund cannot invest more than 5% in a single security (other than government bonds). That leaves the other 50% to play with.
However, a second part of the statute prohibits the fund from investing more than 25% of its assets in a single company. That is the part that I've wondered about with funds like FAIRX. There is an exception if the increased percentage is due to market fluctuations. See Example 6 in the examples below.
Here are some examples of how this statute plays out.
https://www.law.cornell.edu/cfr/text/26/1.851-5

TSUMX. I typed it in here as a courtesy to anyone who's interested. It's certainly not the customary fare. Big $2.5M to get in. I took a look at the coupons on the bigger bond holdings. I dunno how those will do anything right now except to put a drag on results.

Thx Derf. My bad. 1.3-1.5B.

@bee you are welcome and yes about 1 yr. The widespread red is a relatively short term event so far. I find it useful to click through the timeframes of this simple chart periodically. About energy, yes, over 5 years it is still in the red. For a few years, energy was considered a poor investment due to the surge in alternative energy investments and the thinking the transition timeframe to alternatives would likely be fairly short. Now, there seems to be some serious thinking that the transition to renewables will likely occur over an extended enough time frame that the traditional energy sector will remain worthy of investment for at least "several" more years. (I know I still own gas powered cars and my primary house still uses natural gas for heat. Also, I still plan to to take some trips via air once my covid concerns have abated and lots of stuff in my house contains "plastic".) I am presently comfortable having about 10% of my investments in that sector.

@Dennis Baran : Are you talking 1.3-1.5 million or billion ?

Spoke with Ali Motamed, one of the two PMs on the fund. Their strategy has three different products, and as an all-cap fund, it will hard close at 1.3-1.5 AUM, allowing it to invest in smaller companies when they see opportunities there. This was also mentioned in their December commentary and will be repeated in their January commentary when it's published.

@sma3 Thank you for catching my misstep. I’ll (cheerfully) edit earlier post to delete comment.
Here’s the name of DFND - Clearly not a Simplicity offering: Siren DIVCON Dividend Defender ETF
I don’t have any opinion on PFIX as long as folks understand the potentially very high volatility and that it can move both ways. I own a few like that myself. :(
In hindsight, perhaps a 30 year fixed rate mortgage at 2.75% or 3% would constitute an interest rate hedge? In that case, the bank, government or financial institution is the lender / investor.

It’s an interesting snippet. Sorta what my humble non-expert view might be. But one who tends to view worst case scenarios. Off and on there’s been talk of “liquidity problems” in the media. Most recently on Bloomberg’s last Wall Street Week show - and addressed to some length by Blackrock’s Rick Rieder. This liquidity talk always makes me nervous as can cause markets to seize up.
Yes - the long duration assets would be a lot of ARKK holdings. I’ve heard that argument - that rising rates will strangle them. However, they’ve already been choked to death ISTM. So not too sure how much farther down they can go. Wish I were 25 years younger (don’t we all?). Would probably buy some.
@Old_Joe used to subscribe to the Economist. Not sure if he still does. FWIW - most periodicals can be purchased single issue at Amazon and downloaded to most any device having the app. Subscribing to a free trial period and than cancelling is another way to obtain latest issue.

Anybody subscribe and can read the entire article? I just got this snippet, although the argument is familiar
"The Economist offers an insightful big picture overview this week in What would happen if financial markets crashed?:
Today America’s financial system looks nothing like it did before the crashes of 2001 and 2008, yet lately there have been some familiar signs of froth and fear on Wall Street: wild trading days on no real news, sudden price swings and a queasy feeling among many investors that they have overdosed on techno-optimism. Having soared in 2021, shares on Wall Street had their worst January since 2009, falling by 5.3%. The prices of assets favoured by retail investors, like tech stocks, cryptocurrencies and shares in electric-car makers, have plunged. The once-giddy mood on r/wallstreetbets, a forum for digital day-traders, is now mournful.
It is tempting to think that the January sell-off was exactly what was needed, purging the stock market of its speculative excesses. But America’s new-look financial system is still loaded with risks. Asset prices are high: the last time shares were so pricey relative to long-run profits was before the slumps of 1929 and 2001, and the extra return for owning risky bonds is near its lowest level for a quarter of a century. Many portfolios have loaded up on “long-duration” assets that yield profits only in the distant future. And central banks are raising interest rates to tame inflation."

For a contrary and apocalyptic view Lacy Hunt is always worth listening to. He has believed that the debt burden of the US and the world is so huge that it will strangle the economy and create a massive depression.
This is a pretty technical interview, although it is not really a debate between him and Harvey Bassman about what will happen to interest rates in that scenario.
https://www.simplify.us/news-media/keeping-it-simple-ep10-inflation-and-rates-lacy-hunt?utm_medium=email&_hsmi=203561693&_hsenc=p2ANqtz-_hy0mKttax8Lt0RU223QWBcMW4ljj2Xx3VNdImJKr9ZCZT9GaN69IMwvpH1M7P4EPhSvC98uCw10-FCieU-sOMTW5Gxw&utm_content=203561693&utm_source=hs_automation

@hank
I don't see DFND on Simplify website and M* says is from SRN advisors.
Simplify has many hedged ETFs but their descriptions of what they are designed to do is rather vague unless you understand options better than I do.
Bassman is quite specific about PFIX as insurance against interest rates rising and has a fair amount of data on predicting what it will do in various scenarios. He also recommends only small positions, say less than 5 % of a total bond portfolio.
I am not sure that an inverse treasury ETF would not do the same thing, but there you could loose a lot more than 50%

Feb. 11 https://www.invenomic.com/_files/ugd/8592d8_a1ac66bac0af4f1fa27aa3aa0577f808.pdf

@davfor,
Interesting:
1 yr - Still lot of green
5 yr - Energy still negative
Thanks for the link.