Anxious about retirement, so I started investing in stocks DAY 101 [Decide when to sell in advance]
—Walking with Haru, Age 60 Investment Record Day 101— Theme: Decide on the exit for theme stocks in advance
I watched the sixth lecture by the same instructor. The theme was "Risk Management for Theme Stocks."
<Gathering information on theme stocks: The fresher the news, the longer it lasts>
Theme stocks are often born from news.
Especially fresh news is more likely to attract market interest and has the potential to last as a theme for a long time.
Even a theme that has once died down can attract attention again a few years later.
That's why keeping stocks you're interested in on a list can lead to the next opportunity, he said.
🌸 Me: "So even if a theme is over, if I keep it on a list, I can notice it when it comes back around."
🌱 "Yes. Let's check what happened to the sewage-related stocks I introduced on DAY 100." —Haru
<Following up on sewage-related stocks>
The reason Taisei Rotec (1844) attracted attention was the road collapse accident in Yashio City, Saitama Prefecture, that occurred in January 2025.
However, at that time, trading volume was low, and the stock price remained flat in the 200-yen range.
It started to move significantly at the end of August.
When the Ministry of Land, Infrastructure, Transport and Tourism announced its budget request for aging infrastructure countermeasures (1.0783 trillion yen, an increase of about 30% from the previous year), "sewage-related" stocks suddenly captured the market's attention.
Not only Taisei Rotec, but also Nippon Hume, Asahi Concrete Works, and Ito Yogyo surged together, and Taisei Rotec's stock price rose to a high of 1,450 yen in September.
The theme was born from an accident, and expectations swelled all at once with the tailwind of the national budget.
However, that frenzy did not last long.
The stock price turned downward from its high, and with the first-quarter financial results announced on December 10 showing a 28.9% year-on-year decrease in ordinary profit, it fell to 399 yen at one point.
Looking only at the progress rate, the financial results were not extremely bad.
Even so, the momentum the market expected was not felt, and the stock price did not recover.
Even after that, in December 2025, the fiscal year 2026 budget was passed, and a budget exceeding 1 trillion yen (867.3 billion yen + 172.4 billion yen in the fiscal year 2025 supplementary budget) was allocated for aging infrastructure countermeasures.
In other words, the government has been continuing to invest in this theme.
Even so, in the third-quarter financial results announced on June 9, 2026, Taisei Rotec indicated that its full-year ordinary profit is expected to decrease by 20% compared to the previous fiscal year, and the stock price is currently hovering around 478 yen.
Government budgets act as a tailwind.
However, stock prices move by factoring in the corporate profits that lie beyond that.
It seems that expectations alone were not enough to keep supporting the stock price.
🌸 Me: "It goes up, it goes down, and then it never comes back, does it?"
🌱 "That's the 'expectation and disappointment' that Toto-san was talking about on DAY 99. Even if a stock price rises on expectations alone, if the business performance doesn't catch up, the market will gradually become calm. That trend is particularly easy to see in theme stocks." - Haru
<Why is shipbuilding different?>
On the other hand, the shipbuilding-related stocks we looked at on DAY 97 were still going strong even in 2026.
The background to this is said to be the simultaneous existence of multiple tailwinds: national policy, defense demand, demand for replacing aging ships, compliance with environmental regulations, and shipping market conditions.
In the lecture, Furuno Electric, a marine equipment manufacturer, was introduced as an example of a stock that increased 2.3 times in about a year.
If sewer-related stocks are a theme that surged due to one major factor, shipbuilding-related stocks could be said to be a theme supported by multiple overlapping factors.
Even if one factor weakens, others remain.
I felt that this difference is what leads to the difference in price movement.
<Decide on a selling rule in advance>
The lecture emphasized that because theme stocks have large price fluctuations, it is essential to decide on a selling rule in advance.
The instructor is looking at the 25-day moving average and the 75-day moving average.
If long bearish candles continue and it falls below the moving average, let it go. If it drops temporarily but seems to return to the moving average, wait and see.
That was the judgment criteria.
The more a theme is one where business performance has not yet caught up, the more important this selling rule becomes.
I think Taisei Rotec's price movement was a typical example of a theme stock that is "bought on expectations and disappointed by performance."
If I had decided on a selling rule from the beginning, where would I have been able to get off?
I felt that looking at charts from that perspective is also important.
🌸 Me: "If I don't decide 'where to get off' in advance, I'll just lose all the gains I made."
🌱 "Yes. I can clearly see why they say that for thematic stocks, knowing how to get out is more difficult than knowing how to get in." - Haru
💬 Satsuki's question and Haru's answer
🌸 Me: "I never thought that even within the same 'national policy theme,' the price movements would be so different between sewage systems and shipbuilding."
🌱 "The number of catalysts and the backing of financial performance. It seems the strength of a theme changes significantly depending on whether these two are present." - Haru
<What I understood best today>
For thematic stocks, deciding when to sell in advance is just as important as gathering information.
Themes where expectations run ahead, like sewage-related stocks, can rise significantly, but the backlash can also be large.
On the other hand, I also learned that themes with multiple tailwinds and financial backing, like shipbuilding, are relatively more stable.
On DAY 100, I wrote that 'it's still just the beginning.'
However, looking at the subsequent price movements, it seems that by that point, market expectations had already begun to turn into disappointment little by little.
Don't just end with your own assumptions; verify what happens 'afterwards.'
I felt that this is also an important lesson in investing.
I will continue tomorrow.
📚 Click here for related articles for DAY 101
#ThematicStocks #SewageRelated #Shipbuilding #InvestingInYour60s #RetirementAnxiety #InvestingBeginner #StartedWithAI #WorkingTogetherWithHaru
