To a large extent, I agree with you that 12 month periods are baked in as intuitively obvious. That said, I disagree that the 12 month period must be tied to a calendar year.
When I look at one year performance, I'm looking at the past 12 months (e.g. 10/17/17 to 10/27/18), or maybe the past 12 full months of performance (9/30/17 to 9/30/18). For one year performance I'm certainly not going to ignore what's happened between January and October of this year (i.e. I don't look at 2017 data as a meaningful representation of how a fund did over the past year).
There are even special cases for RMDs that get away from calendar years: you have a fifteen month period in which to take your first RMD (the year you turn 70.5 and up to April 1 of the next year); so you can also take two RMDs within a single calendar year. In addition, there was a calendar year in which no RMDs were required (2009).
Further, for 401(k)s where the fiscal year doesn't match the calendar year, assuming no withdrawals have been made, the value of the account used to compute the RMD is the account value at the end of the fiscal year, not the value at end of the calendar year (Dec 31). Here's a page discussing this:
https://www.irahelp.com/forum-post/21980-rmd-fiscal-year-based-profit-sharing-plan
For performance comparison purposes, funds must use standardized periods. This is to prevent cherry picking. For example, they can't advertise their performance starting the day the market hit bottom. The use of calendar quarters for comparisons is indeed arbitrary, but the very arbitrariness of these dates means that no fund is benefited or disadvantaged by the choice of dates.
Even here, the yearly periods are not calendar years; they cover twelve months through the end of the last quarter, not the last year. Yes, 12 month periods are baked in. No, figures are often not anchored on Jan 1, except YTD figures. And on Feb 25, does one really care about YTD?
How to Read a Performance Advertisement that Describes a Mutual Fund’s Total Return
https://davisfunds.com/downloads/04readingfndadv.pdf

Dunno how much it’s down. Don’t much care. But I’ll note here that percentages can be very misleading.
Example A: If your portfolio fell by 25% in one year, you would actually need to gain more than 33% in the following year to “break-even” again.
Example B: How many years in succession can your portfolio experience a 25% decline?
Think 4? Actually, in hypothetical terms, it could fall by 25% per-year every year - forever.
Are you feeling lucky?

The author makes a worthwhile point. The “YTD return” a lot of us focus on is based on an arbitrary 12-month Earth year beginning January 1st. I find YTD return a curiosity, but don’t get too bent out of shape when it’s negative. Viewing 3 or 4 successive years’ total returns together yields a better perspective. And when you get out to 10 years and beyond, total cumulative return (often viewed as a yearly average) becomes quite important.
In a sense, we’re locked-in to paying attention to the 12-month calendar year. Not only is it the “language” most analysts and market observers communicate in, but there are some practical considerations. Foremost, Uncle Sam takes notice. He constructs your RMD (if over 70.5) so that distributions must be taken on a yearly basis. If you do a Roth conversion there’s normally a 5-year holding period before gains can be withdrawal penalty free. Income taxes are based on yearly income / gains & losses. In preparing a household budget, the 12-month year is easiest to work with. Some household expenses, like insurance premiums or newspaper subscriptions, come due on a yearly basis. College tuitions may be paid on a yearly or semi-yearly schedule. Expensive vacations (think: sun-belt) are best planned / funded according to the yearly calendar. And our automobiles become one model year older roughly every 12 months - affecting depreciation, resale value and insurance considerations.
So in a nutshell, in terms of significance, YTD and 12-month calendar numbers are pretty baked in the cake and it’s entirely natural for Earthlings to take notice. If you inhabited Mars or one of Jupiter’s intriguing moons you would probably subscribe to some alternative way of viewing short term investment performance.

I read a thin volume years ago: "https://www.amazon.com/Lectures-Relativity-Charles-Proteus-Steinmetz/dp/1933998040
It had me thinking that I almost had a handle on that stuff.

Blows my mind too. Sometimes, however, I come close to understanding Einstein’s view of gravity (somehow tied-in to the the theory of relativity) - but than it escapes me. As I understand his view of gravity, everything is traveling in a straight line (including orbiting planets). But because space itself is warped by the mass of large objects, objects like planets only appear to be moving in circular orbits.
From a practical standpoint, would an equity position opened on Earth by an “Earthling” from his near-the-speed-of-light spacecraft appreciate in Earth years? If so, the traveler would be unimaginably wealthy once he eventually returned to earth - and still young enough to enjoy his new found wealth to the fullest. :)

FYI: The S&P 500 ended at -1.7% to 2658, after earlier falling nearly 3% and breaching the 2637.68 level that would place it 10% below its last record. That would put it in correction territory for the first time since February’s selloff.
The Nasdaq Composite fell 2.0%, paring much of Thursday’s rebound and putting it down about 10% for the month, while the Dow Jones Industrial Average declined 1.1% to 24688. A close below 24145.55 would put the blue-chip index in correction territory.
Markets around the world have been caught up in a whirlwind week marked by intraday drops and sharp rebounds. Worries about corporate revenue slowing and whether a slowdown in China and Europe growth could spill over into the U.S. economy have sent U.S. stocks into a tailspin, putting major indexes on course for their worst month in several years.
The recent stampede by investors has erased about $5 trillion in value from global stock and bond markets in October alone. But that shouldn’t be severe enough to affect the economy, for now, according to economists at Deutsche Bank.
Still, unless the markets regain their footing soon, the pressure for the Federal Reserve to reassess their monetary policy will continue to mount, they said.
“Academic studies of the wealth effect find that households and companies don’t react to short-term fluctuations in their wealth but instead react to a moving average of where their wealth levels are,” said Torsten Slok, chief international economist at Deutsche Bank Securities, said in a note to clients.
Regards,
Ted
Bloomberg Evening Briefing:
https://www.bloomberg.com/news/articles/2018-10-26/your-evening-briefing
Bloomberg:
https://www.bloomberg.com/news/articles/2018-10-25/asia-stocks-set-to-rally-on-u-s-gains-bonds-slip-markets-wrap?srnd=premium
WSJ:
https://www.wsj.com/articles/global-stocks-resume-declines-1540541081
MarketWatch:
https://www.marketwatch.com/story/us-stock-futures-under-pressure-after-amazon-google-disappoint-2018-10-26/print
IBD:
https://www.investors.com/market-trend/stock-market-today/stock-news-today-amazon-earnings-alphabet-earnings/
Reuters:
https://www.reuters.com/article/us-usa-stocks/wall-street-resumes-selloff-sp-flirts-with-correction-idUSKCN1N01JN
CNBC:
https://www.cnbc.com/2018/10/26/stock-market-us-futures-show-drop-for-dow.html
U.K.:
https://www.marketwatch.com/story/ftse-100-tumbles-to-near-2-year-low-as-global-stock-rout-resumes-2018-10-26/print
Europe:
https://www.marketwatch.com/story/european-stock-markets-tumble-sharply-lower-to-end-an-ugly-week-2018-10-26/print
Asia:
https://www.cnbc.com/2018/10/26/asia-markets-wall-street-ecb-currencies-in-focus.html
Bonds:
https://www.cnbc.com/2018/10/26/us-bonds-treasury-prices-higher-amid-market-volatility.html
Currencies:
https://www.cnbc.com/2018/10/26/forex-markets-dollar-yen-stock-markets-in-focus.html
Oil:
https://www.cnbc.com/2018/10/26/oil-markets-saudi-arabia-crude-supply-in-focus.html
Gold
https://www.cnbc.com/2018/10/26/gold-markets-stock-markets-ecb-in-focus.html
WSJ: Markets At A Glance:
https://markets.wsj.com/us
Major ETFs % Change:
https://www.barchart.com/etfs-funds/etf-monitor
SPDR's Sector Tracker:
http://www.sectorspdr.com/sectorspdr/tools/sector-tracker
SPDR's Bloomberg Sector Performance Pie Chart:
https://www.bloomberg.com/markets/sectors
Current Futures:
https://finviz.com/futures.ashx

FYI: Investors use calendar years as a period of measurement. How did the market do last year? Most of us view our investment performance “year-to-date” meaning how the investments have changed in value since January 1. Advisors conduct annual (or quarterly) reviews comparing investment returns to benchmarks which are sometimes appropriate but often are not.
Below are two lists of annual returns for a 60/40 portfolio that is hypothetically invested 60% in the S&P 500 Index and 40% in the Bloomberg Barclays U.S. Aggregate Bond Index. The author removed the calendar years on purpose. Take a look at the series of returns and try to imagine experiencing them in succession.
Regards,
Ted
http://blairbellecurve.com/calendar-years-are-arbitrary/

Hi @bee: Years back I did at one time own ODMAX but sold it as I aged and got more conserative. Back then, I also owned NEWFX and retained it. Also, back then, my neutral allocation in the growth area of my portfolio was about 25% today it is 15%. In addition, years back I also owned DEMAX. These three funds comprised my emerging markets sleeve. Now, I am down to one emerging market fund NEWFX but thinking of adding DWGAX in the growth & income area of my portfolio in my global equity sleeve as it pays a quarterly dividend.

NEWFX is one of my three holdings found in my global growth sleeve. It has been a long term holding for me and one that I plan to continue to hold for a good number of years to come.

One of my mutual funds (FDSAX) invest about one third of its money in the Dogs of the Dow strategy (ten positions) and the other two thirds (twenty positions) using the same type strategy for picking stocks from the broader market omitting picks form the financial and utility sectors. I have owned this fund for a good number of years and feel it has served me well. It use to reset its portfolio in the fall of each year; but, in recently viewing its holdings I noticed portfolio changes now seem to be made more often.

For buy-and-hold investors, I don’t see the problem with THOPX. I owned it for a while, including its swoon a few years ago, but its returns over 1, 3, 5, 10 years have been excellent. I don’t understand why M* bashes funds like THOPX but continues to tout funds like MWTRX that have had miserable returns in recent years while becoming bloated with assets. Many so-called quality bond funds have gotten killed by rising interest rates and have seemingly done little or nothing to ease the pain for investors. As long as interest rates continue to rise, investors seeking quality apparently would be better served by ultrashort bond funds, money markets or CD ladders.

We have owned THOPX in the distant past and in recent years, missing it's period of poor performance by blind luck. It's performance of late has been outstanding. M* has long questioned the small team at Thompson and has expressed doubts but it's rare for them to issue a "shouldn't buy" warning. Anyone here consider this article actionable? Anyone have a replacement in mind? When I started building my position in THOPX it was because risk free options were yielding near zero. Now the yield here isn't so great compared to the zero risk choices. Something to think about.

Good analysis by several. I like the ultra-short (TRBUX) mentioned above. Use it as a “cash equivalent” (Not all ultra-shorts are managed as well.). Yet, even over the shorter 5 year period, it lags RPSIX by about a point and a half. So, if willing to tolerate a little more volatility, investors would have been better off in RPSIX.
Another income fund I own is DODIX. i’ve long allowed a smaller portion (no greater than 50%) to count as part of my “cash equivalent” holdings. Of course it’s not really cash - but for allocation purposes I’m willing to include it. DODIX has a longer history than TRBUX. So a 10 year comparison is possible. Here RPSIX still wins with a 6.28% return while DODIX netted 5.61%. Again - you need be willing to accept more volatility to reap the additional income with RPSIX.
While I’m not “married” to TRP (borrowing Crash’s words), it’s my single largest fund manager and has 100% of my Traditiinal IRA. So, I’ll stick with the 15% allocation to RPSIX. We’ve known for 10 years that bonds would suffer when the emergency Fed easing slowed or stopped and rates normalized / rose. Nothing too startling here. Yes, the foreign securities have taken a toll on the fund. I thought PRELX a brilliant idea when introduced. Unlike most of their international / EM bond funds, Price does not hedge this one against currency fluxuations. So the strong dollar has really hurt it. I’ve owned it before but doubt I will again.

I’ve owned RPSIX for 15+ years because it seemed like the best option available at TRP and provides a broadly diversified income exposure. This is its worst year I can remember in comparison to comparable funds and it seems to be due to its large stakes in PRCIX (New Income) and foreign/EM bonds. As a result, it has performed poorly as interest rates have risen. So, for the first time ever, I shifted about two-thirds of my holding in RPSIX to other less interest-rate sensitive bonds funds — namely TRBUX (ultra short) and PRFRX (floating rate). When interest rates finally seem to be stabilizing, I will probably move the money back into RPSIX.
In the past, RPSIX’s primary weakness was its 10-20% stake in dividend stocks, which hurt returns in bear markets. However, this year has shown that it’s also vulnerable to rising interest rates.

I’m intrigued myself about the fund’s lackluster performance. But like I said earlier, it’s a hard one to classify. Even Lipper (where I normally look) has it scored 3 (out of 5. Over 5 years it hasn’t even beaten their ultra-short (TRBUX) by a full two points. Go figure.
Exposure to PRFDX (Equity Income Fund) seems to have helped in recent years, so rule that one out as the detractor. All I can think is it might be tilted heavier towards high quality (read “rate-sensitive”) bonds than I had assumed or might prefer.
I think a fund like that ought to be able to hold 20-30% in below investment grade debt (and EM). I’ll guess RPSIX is not that high. Another thought: They probably have a good slug of inflation protected bonds in the mix - and those might have been a drag in recent years.
Don’t have time to search for the credit quality breakdown. If anybody has that for RPSIX please share.

FYI: The early October jolt of stock market volatility seemed to awaken investors briefly from a relative sense of calm and reminded us that pullbacks and downside risk are part of the price to be paid for upside performance.
Despite just about every investing fear imaginable, any long-term snapshot of stock market performance will illustrate a persistent bias toward positive performance. Whether looking back 10, 50, 100 years or more, the basic economics of investing in a broad range of publicly traded companies is difficult to deny.
On the subject of whether more market shake-ups are ahead, most financial advisers are rightly positioning the possible impact of the midterm elections along the lines of: "We're long-term investors" or "We don't have a crystal ball."
Regards,
Ted
https://www.google.com/search?source=hp&ei=pDfLW_bhBaOVjwTJrbTABw&q=Investors,+don't+lose+sleep+over+the+midterm+elections&btnK=Google+Search&oq=Investors,+don't+lose+sleep+over+the+midterm+elections&gs_l=psy-ab.3...3030.6789..8754...0.0..0.131.233.2j1......0....1j2..gws-wiz.....0..33i299.2_tpbvoSjLQ

Here's a piece on one of John Hancock's plans. It has a 1.69% plan fee - which might be paid by the employer, the employee, or split. If the employee pays that fee or part of it, it could make the fund expense look higher. The example in the article takes a 0.18% underlying fee expense and adds the 1.69% plan fee to come up with a 1.87% fund fee.
https://www.employeefiduciary.com/blog/john-oliver-should-be-upset-his-hancock-401k-fees-are-too-high
The column is a discussion of the Hancock plan John Oliver presented a couple of years ago (and was linked to by MFO, somewhere). Oliver starts talking about the plan around 12:00 in the video:

When things level out intend to buy some more

The problem is, how will you know when it's the time when things level out? It's easy to look back and see it as such.
I added healthcare at the start of this downturn, but it kept going down further, so now I'm not sure if I should hold.
Sold most of my EM, which after almost 2 years, turned out to be much ado about nothing, but at least I didn't lose.

FYI: Ten years after financial markets around the world tumbled toward chaos, they have an anniversary present for you: more stress.
After a gain of nearly 7 percent in the third quarter, October ushered in a rout in the U.S. equity markets. The Standard & Poor’s 500 index plunged 6.7 percent from Oct. 3 to Oct. 11, with Asian and European equities following suit. On Oct. 12, the S&P 500 bounced back with a 1.4 percent gain.
The equity market drama comes amid recent violent surges in Treasury yields and rising trade tensions. As earnings season begins, fear is mounting that these forces will cut into corporate profits and sound the death knell for growth stocks. Meanwhile, a strong U.S. dollar and heavy debt loads in many emerging markets, together with the trade turmoil, are leading to lower estimates for global economic expansion.
It’s a challenging period—and an opportunity. The market’s inevitable cycles, however painful, are made for disciplined investors.
Regards,
Ted
https://www.bloomberg.com/features/2016-how-to-invest-10k/?srnd=premium

FYI: Gold prices have rallied recently, but the metal’s behavior in recent years makes it a tricky wager for options investors.
Regards,
Ted
https://www.barrons.com/articles/gold-investing-options-1539918983?mod=djem_b_Weekly Feed for Barrons Magazine