[Net Worth Update] August 2026: JPY 10,843,342 — Up JPY 236,733 for the Month and JPY 2.71M Year Over Year to a New High

Hey there, it’s Hirokichi!

I finished tallying up my assets for August 2026. My total came to 10,843,342 yen, up 236,733 yen from the previous month. The Nikkei 225 climbed into the 68,000s mid-month and then got sold off hard, so it was a rough ride, but the month closed in the green.

The Result: 10,843,342 Yen, Up 236,733 Yen (+2.23%)

As of the end of August 2026, my total assets stand at 10,843,342 yen. That is up 236,733 yen from 10,606,609 yen a month earlier, a gain of 2.23%. It is the third straight monthly gain since I crossed the 10 million yen mark.

The chart shows the dip to 9,283,846 yen in March, followed by five consecutive months of gains from April onward. Compared with 9,143,959 yen at the start of the year, I am up 1,699,383 yen in eight months.

To be honest, I got nervous several times watching the numbers this month. On the day the Nikkei crashed in mid-August, a big chunk of my unrealized gains (profits on holdings I have not sold) vanished, so I had no idea how the month would end until I ran the final tally.

The Breakdown: iDeCo at 35%, NISA at 48% Combined

Here is where everything sits at the end of August.

iDeCo (US mutual funds): 3,822,771 yen (35%)
NISA US ETFs: 2,496,447 yen (23%)
NISA mutual funds: 1,384,541 yen (13%)
NISA Japanese stocks: 1,333,385 yen (12%)
Junior NISA: 1,136,043 yen (10%)
US bond ETF: 708,755 yen (7%)

What the pie chart makes clear is that US assets (iDeCo, NISA US ETFs, NISA mutual funds and the US bond ETF) make up roughly 78% of the total, while Japanese stocks account for only 12%. With a tilt that heavy toward the US, the yen-dollar exchange rate feeds straight through to my total.

By account type, New NISA (Japan’s tax-free investment account, covering my mutual funds, US ETFs and Japanese stocks here) is 48% and iDeCo (Japan’s individual defined-contribution pension plan) is 35%. Those two hold more than 80% of everything I own. Getting the bulk of my money into tax-free accounts is an unglamorous move, but I think it matters a lot over the long run.

What Drove the Month: A Volatile Nikkei and a 3.0% Gain for the S&P 500

Here is the month-over-month change by asset class.

iDeCo: +119,487 yen (+3.23%)
NISA mutual funds: +112,488 yen (+8.84%)
NISA US ETFs: +55,192 yen (+2.26%)
Junior NISA: +15,066 yen (+1.34%)
NISA Japanese stocks: -11,077 yen (-0.82%)
US bond ETF: -15,823 yen (-2.18%)

What the chart shows is that US equity funds did nearly all the work this month. iDeCo and my NISA mutual funds alone added 231,975 yen, which accounts for almost the entire 236,733 yen increase in my total.

So why did it play out that way? Here is a look back at August.

US stocks were firm, with the S&P 500 up 3.0% for the month and back near record territory at 7,677 points in late August. Cooling inflation, easing worries about the Middle East, and lower long-term yields on the back of falling oil prices combined to bring buyers back into the semiconductor names that had been sold off earlier in the month. For my portfolio, my iDeCo and NISA US equity funds captured that move directly.

Japanese stocks finished the month higher on paper, but the path was messy. The Nikkei 225 ran from 64,362 at the end of July to 68,713 on August 14, then dropped sharply on Middle East concerns and rising long-term yields, including one session down 2,134 points, before settling back in the 66,000s. My NISA Japanese stocks finished at -11,077 yen, the only equity bucket in the red, because they caught that second-half decline.

The other drag was my US bond ETF at -15,823 yen. Long-term US yields rose at one point during the month, and since bond prices move the opposite way, the value came down. At 7% of my portfolio, though, the effect on the total was limited.

The quiet hero this month was the exchange rate. The yen weakened from 157.40 per dollar at the end of July to the 159 range by late August. Because I measure everything in yen, a weaker yen lifts the yen value of my US assets on its own. The flip side is equally true: in a month when the yen strengthens, my total can shrink even if US stocks go up.

Up 2,713,462 Yen Year Over Year: 3.7 Times Larger in Five Years

Here is the same end-of-August snapshot going back six years.

August 2021: 2,936,302 yen
August 2022: 4,267,343 yen
August 2023: 5,194,078 yen
August 2024: 6,325,460 yen
August 2025: 8,129,880 yen
August 2026: 10,843,342 yen

That is a year-over-year gain of 2,713,462 yen, or 133.4%. What strikes me about this chart is that the size of each annual gain keeps growing. From 2021 to 2022 I added 1,331,041 yen; over the past twelve months I added 2,713,462 yen. My monthly contributions have actually gone down, not up, so the difference comes from the principal being larger, which turns the same percentage move in the market into a much bigger yen figure. Being 3.7 times larger in five years is something I honestly never pictured when I started.

A Quick Word on Each Account

iDeCo is at 3,822,771 yen, now my single largest holding. It is one US mutual fund, and the fact that I cannot touch it until age 60 has kept me from doing anything clever with it, which turned out to be a blessing.

New NISA comes to 5,214,373 yen across mutual funds, US ETFs and Japanese stocks. It is up 1,643,127 yen year over year (146.01%), the fastest growth rate of anything I hold.

The US bond ETF sits at 708,755 yen. Its value falls whenever yields rise, but I hold it for the distributions rather than price appreciation, so the swings do not bother me much.

Junior NISA is at 1,136,043 yen. That money is earmarked for my children, so I leave it alone.

Monthly Contributions Are 15,000 Yen: Education Costs Come First Right Now

Here is what I am currently contributing each month.

eMAXIS Slim US Equity (S&P 500): 5,000 yen
Tracers Nikkei 225 High Dividend Yield Stock 50 Index (odd-month distribution type): 3,000 yen
Rakuten Schwab US Dividend Equity Fund (quarterly settlement type, “Rakuten SCHD”): 2,000 yen
iDeCo: 5,000 yen

That comes to 15,000 yen a month, which is a small number for a blog reporting a portfolio above 10 million yen. The reason is straightforward: a large share of our budget is going to cram school and other exam preparation costs for our two children.

My son is in his final year of elementary school and takes his entrance exams next March; my daughter is in her second year of junior high and sits hers the year after. Cutting the education budget to invest more was not a trade our family was willing to make. Investing can be made up later. My kids only get one shot at these exams.

The Plan Ahead: Holding Steady Until April Two Years From Now

I am leaving contributions at 15,000 yen a month going forward. I plan to hold at this level until after April two years from now, once my daughter’s exams are behind us.

I will admit that watching a strong market makes me think “I should have put more in.” But forcing contributions higher, squeezing the household budget, and ending up having to sell everything partway through is the worst thing you can do as an investor. Small is fine. Not stopping is what counts.

To put it in numbers: of this month’s 236,733 yen increase, the 15,000 yen I contributed accounts for just 6%. The other 94% came from assets I had already built up doing the work on their own. At this size, staying in the market matters far more than the size of any single month’s deposit.

Wrapping Up

August 2026 closed at 10,843,342 yen, up 236,733 yen for the month and up 2,713,462 yen (133.4%) from a year ago. The Nikkei whipsawed, but US equity funds carried the total higher.

If there is one takeaway, it is this: in months when your contributions are small, the market, not your effort, decides how much your portfolio grows. The reverse is also true, which means a bad month will shrink your assets no matter how much you deposit. So do not get carried away in good months, and do not bail out in bad ones. With contributions down to 15,000 yen, that is about all I can control.

I will keep recording this month by month. Slow and steady. See you next time!

Last month’s record: [Net Worth Update] July 2026: JPY 10,606,609 — Up JPY 194,719 to a New All-Time High Despite the AI Chip Selloff

See the full archive of my net worth updates (2021 onward)

日本語版はこちら → 【総資産公開】2026年8月は10,843,342円！前月比+236,733円、前年同月比+271万円で過去最高を更新

* This article is for informational purposes only and is not investment advice. Please invest at your own responsibility.