[All Figures Revealed] The 3 Days of Tungsten Price Surges: I'll Disclose the Breakdown and Unit Prices of the 2.14 Million Yen I Invested

I'll start with the conclusion. With China's tungsten regulations, what I bought wasn't mining stocks or material manufacturers."Three processing companies with plenty of inventory"—I put 2.14 million yen into them over 3 days. This is the actual measurement of my account as of August 2026.

What no one tells you is that in news like this, what really works is the "order in which price increase notifications are issued." People watching price charts usually arrive second.

[Record] August 4, 2026 (Tue)
・09:02 China notifies that it will further tighten export permits for tungsten-related products
・09:05 Rare metal ETFs, up from the opening by +6.8%. Social media is flooded with "It's the mines, it's the mines"
・09:12 I didn't buy a single mining share, but bought 700 shares of Fuji Die (6167) at 1,283 yen
・Current unrealized gains, total for the 3 companies is +264,000 yen. I haven't taken any profits yet

I will write this in chronological order. By the way, I lost 1.28 million yen on the same theme last year. I'll release all those records too.

[What you will learn in this article]
1. The mechanism of how you get taken when buying "material stocks" due to tungsten regulations
2. February 2025, the record of the 3 weeks where I lost 1.28 million yen
3. The 3 processing companies I bought and the breakdown of the 2.14 million yen (dates, unit prices, number of shares)
4. What the operations side looks at first is not the price, but the "inventory turnover days"
5. The 4-stage order in which price increase notifications are issued, and where to look before disclosure
6. A quick reference table for the 3 companies' positions and stop-loss lines
7. A checklist for deciding when to close positions
📌 Also recommended
・[Position Record] Bank of Japan's purchase request, 3 stocks I picked up as a former interest rate desk trader
・[Pre-market Memo] 3 sectors to buy during high oil prices, capturing dividends

🔩 Buying material stocks due to tungsten regulations will get you taken

About 80% of the world's tungsten supply comes from China. So, thinking "exports will be tightened → prices will rise → mines and materials will rise" seems like a sound way to read the market.

But that is where you get taken.

The reason is simple. There are almost no pure listed stocks for "tungsten mines" in the Japanese market. Therefore, what gets bought are resource trading companies, ETFs with rare metal names, or mid-cap stocks that are only slightly related. In other words, "associative buying without real ammunition backing." Associations end the moment the association is broken.

On the other hand, the processing side is different. Carbide tool manufacturers have months' worth of raw material powder and chips piled up in their warehouses. If a price increase is approved, that inventory becomes a state of "selling at a high price while having purchased at a low price." What you are riding here is not an association, but the numbers that appear in financial results.

When I was at the desk, whenever news like this came out, what I had to do was already decided. I wouldn't look at the price. I would look at which tier the price increase notification for business partners would be issued to first. That's all.

💡 One action you can take today: For the related stocks you hold (or are targeting), try sorting them into either "the side selling the raw material" or "the side using the raw material." The order in which they rise is different.

When I started this kind of event trading, I only remembered "what I bought" and couldn't recall "why I bought it" later. Now, every time, I write only 3 lines on graph paper: date, stock name, and reason. Just by keeping one graph paper trade record notebook in my bag, the number of times I added to positions based on emotion, like I did last year, has decreased. It costs less than a single coin, so it doesn't hurt even if you fail.

📉 February 2025, the record of when I lost 1.28 million yen

I'll leave last year's record here too. Please don't skip it. I have already done and failed at what you are likely about to do right now.

[Record] February 2025 February 7 (Fri)
・09:30 China announces additional items for export control. Theme stocks move all at once
・09:41 Jumped into mid-cap resource stocks. Average acquisition 1,742 yen × 800 shares = 1,393,600 yen
・09:58 Up 110,000 yen
at the day's high. If I had taken profits here, I would have recovered the full amount・February 28 Withdrew at 1,142 yen. Lost 480,000 yen
・Furthermore, lost 800,000 yen on rare metal-related ETFs. Total loss of 1.28 million yen

What did I do wrong? I bet on "the material rising," but what I bought was "a company whose profits do not increase even if the material rises." If the purchase price rises, the selling price must also be raised accordingly. Until the price increase negotiations are successful, gross profit is actually eroded.

I still remember what my boss at the desk told me. "If you're going to buy on regulatory news, buy the side that is raising prices. Don't buy the side that is having prices raised on them." At the time, I ignored that and paid 1.28 million yen in tuition. The date I wrote in red in my notebook is still there.

After this failure, I started recording my trades using the same format every time. This is to break things down into procedures rather than emotions. To keep my long-term accumulation and short-term event trading from getting mixed up in my head, I base my approach on the JUST KEEP BUYING philosophy, and I keep my event-based positions in a separate account and notebook. If you don't separate your foundation from your bets, you'll never understand the cause of your failures.

🏭 The 2.14 Million Yen Breakdown: I Bought 3 Processing Companies

I originally intended to keep this part behind a paywall, but I'm releasing it for free this time. The dates and unit prices are exactly as they were.

【Record】2026 August 4th - August 6th
・August 4th (Tue) 09:12 Fuji Die (6167) 1,283 yen × 700 shares = 898,100 yen
・August 5th (Wed) 13:47 Dijet Industrial (6138) 505 yen × 1,300 shares = 656,500 yen
・August 6th (Thu) 09:04 Nissin Tool (6157) 2,345 yen × 250 shares = 586,250 yen
・Total Invested 2,140,850 yen

Why these three companies? Because they are all on the 'cemented carbide' processing side, and they are companies where inventory assets are heavy relative to sales. Fuji Die handles cemented carbide wear-resistant tools, Dijet Industrial handles cutting tools, and Nissin Tool handles small-diameter end mills. Their customer bases are also diversified across automotive, mold, and semiconductor sectors.

And all three companies have small market capitalizations. With large general manufacturers, the cemented carbide division might not even account for 10% of the total. Even if the theme hits, the financial results get diluted. I chose them based on 'Theme Purity'.

On the morning of August 4th, I was speechless looking at the order board because while stocks with mining-like names were up over 6%, these three processing companies were basically flat compared to the previous day. Despite the same material, there was a time lag of about a week in price movement. Those 30 minutes were the most profitable.

When you calculate unit price × number of shares in your head, you're more likely to be off by a digit when you're panicked. Since I started keeping a calculator in front of my screen, my order errors have dropped to zero. I just keep one slim, stylish calculator on the corner of my desk. It costs around 2,000 yen, and I like it because it doesn't look like typical office equipment.

⚠️ However, I must clarify that this is a record of my own positions, not a recommendation. I did not write this with the assumption that you would copy my unit prices or share counts.

🧮 What Institutional Investors Look at First Isn't Price, but Inventory Turnover Days

This is the one thing I want you to remember and take home today.

When news of raw material regulations breaks, the first thing institutional investors open isn't a commodity price chart. It's the 'Inventory Assets' section of the financial statements and the 'Inventory Turnover Days' derived from it. I guarantee it.

The calculation is just this.

Inventory Turnover Days = Inventory Assets ÷ Cost of Goods Sold × 365. The longer this number is, the longer they have been holding 'cheaply acquired inventory.' When a price hike is passed on, gross profit expands by that much. Conversely, for companies where this number is only 30 or 40 days, the rise in raw material costs is reflected in their costs almost immediately. In other words, they are on the side that gets hit by high material costs.

The three companies I picked all had between 146 and 188 days. That means they are holding nearly half a year's worth of inventory. It's not a number to be praised for a manufacturer, but in this specific situation, it acts as a shield.

When you pick up small-cap stocks like this in units of hundreds of thousands of yen, trading commissions directly affect your performance. If you plan to diversify across three companies and add to your positions on dips, having a separate account for events with the lowest industry-standard commissions for Japanese stocks will clearly change your annual friction costs. The fact that US stock commissions are 0 yen is also useful when looking at geopolitical themes from both sides.

By the way, Chi-chan sent me a LINE last week asking, 'Is tungsten for dentist drills?' Close. It's used in dental burs, but the main target is factory cutting tools. I know she only saves money, and I've never laughed at her for that. But when changes like this happen, if you don't have anything in your account, 'the change itself becomes irrelevant to you'. That's the only thing I told her.

Were you watching the material side or the processing side for this theme? Let me know in the comments. Because where people look for the same material varies quite a bit.

💎 What you get in the rest of this (paid part)
✅ A calendar table of the '4-stage sequence' for price hike notifications (including business days from the regulation announcement)
✅ The sites that officials hate, where you can see notifications 2-10 business days earlier than official disclosures
✅ A quick reference table with stop-loss lines and profit-taking conditions for my 3 positions
✅ A calculation template to roughly estimate inventory valuation gains (demonstrated with Fuji Die)
✅ 7-item checklist for deciding when to exit
From here on, I will lay out that 'sequence,' 'where to look,' and 'how to get out,' all with the numbers. If you face the next regulation news without knowing this, you will end up in the same position I was in last year.

📅 The 4-stage sequence for price hike notifications

First, I'll start with the main point. Taking the day the regulation is announced as Day 0, the price hike notifications arrive in this order. This is the average of the past three times I've recorded in my notes (the gallium-based one in 2023, February 2025, and this time).

I entered between August 4th and 6th, when (1) had already peaked and (3) was still dormant. This "valley between (1) and (3)" is the easiest to capitalize on.

And here is the part that the official sources don't really want you to touch.

“Notifications of price revisions for (3) are often released as PDFs in the 'News' section of the company's own website before they appear in TDnet's timely disclosures.” Since these are guides for business partners, there are cases where they don't fall under disclosure obligations. That's why, just by bookmarking and checking the news sections of 10 processing manufacturers every morning, you can find out 2 to 10 business days ahead of the market.

It's neither illegal nor insider trading. It's placed in a location anyone can see. It's just that no one is looking. It's not so much that you lose if you don't know this, but rather that only those who know are picking it up in the valley.

💡 1 action you can take today: Bookmark the "News" pages for Fuji Die, Dijet Industrial, Nissin Tool, OSG, and Mitsubishi Materials, and add them to your morning rounds. Takes 3 minutes.

📊 Quick Reference Table for My 3 Positions and Stop-Loss Lines

I'll tell you the numbers from my account. I'll put them out exactly as they are, without any adjustments.

The stop-loss is uniformly set at ▲10% of the purchase price, and the primary profit-taking is designed to drop only half at +20%. I decide on this asymmetry (1 unit of risk to 2 units of return) before placing the order. In my definition, entering without deciding on the price range is not investing.

Inventory turnover days are rough estimates I calculated myself from the latest quarterly financial reports. You can do it in 5 minutes too, just by picking up the inventory assets and cost of sales and dividing them.

And I'll write down the most important premise. “The reason for these 3 companies will disappear as soon as the regulations are relaxed.” That's why I've also set a deadline. I've set the holding deadline until the quarterly earnings in mid-November 2026, and if the price hikes haven't appeared in the numbers by then, I'll drop half even if I'm sitting on unrealized gains. I'm looking at this as a position held until autumn.

🧮 Calculation Template for Roughly Estimating Inventory Valuation Gains

The procedure for an outsider to roughly estimate "how much will profits increase due to price hikes?" This is the same thing that securities company reports are doing, if you boil it down.

① Roughly set the ratio of raw materials and work-in-progress to inventory assets at 70% ② Multiply by the assumed product price hike rate ③ Resulting amount ÷ Company's planned operating profit = Boost rate. I'll demonstrate with Fuji Die. These are the numbers I used.

・Inventory assets: approx. 5.8 billion yen
・Of which raw materials/work-in-progress (70%): approx. 4 billion yen
・Assumed product price hike rate: 12%
・Boost amount: 4 billion yen × 12% = approx. 480 million yen
・Against the company's planned operating profit: roughly a 20% plus boost

A note of caution here. This is “a rough estimate close to the upper limit, assuming the inventory is completely sold off.” In reality, the price hikes won't pass through in their entirety, and selling, general, and administrative expenses will also rise. I look at the resulting number by cutting it in half. Even so, if it's a 10% boost, it's sufficiently effective as a stock price for a small-cap stock.

The real way to use this template is for comparison. Do the same calculation for 5 candidate companies and line them up in order of the highest boost rate. I did that, and the top 3 companies became my current positions. I didn't buy 4th and 5th place because their boost rates were in the low single digits.

Honestly, the task of picking up inventory assets and cost of sales from the quarterly financial reports is only a hassle the first time. Once you know where everything is written, it takes 5 minutes from the second time on. Just to overcome that first time, I keep a copy of A Book That Makes Financial Statements Easy to Read on hand, which explains how to read a balance sheet with diagrams. It's around 1,500 yen and is thin enough to finish reading on your commute.

✅ 7-Item Checklist for Exit Decisions

Summary so far: ① Processing, not materials, ② Companies with long inventory turnover days, ③ Price hike notifications move stock prices at the third stage, ④ Stop-loss ▲10% / Primary profit-taking +20%. This is the entry point.

The problem is how to get out. The truly difficult part about thematic stocks isn't buying them, but realizing when the reason for buying has disappeared. Here are the 7 items I check every Sunday night. If even one applies, I sell off half.

・Reports emerge that the Chinese side is easing export permit operations
・Related prices in Shanghai have dropped by more than 15% from their recent highs
・No additional price hike notices from processing manufacturers have been issued for over 2 weeks
・Trading volume of my holdings has returned to the level it was at before the sudden surge, based on a 5-day moving average
・Automobile production plans (domestic four-wheelers) have been revised downward
・Inventories in financial results have decreased by more than 10% compared to the previous quarter (the shield of inventory is thinning)
・I have started thinking, "It should bounce back soon"

The last item is the most effective. Last year's loss of 1.28 million yen was the result of ignoring this and holding on for 3 weeks. Once you enter a state of holding based on feelings rather than numbers, that position is no longer under your control.

I write this Sunday night check in the same space in my planner every week. Rather than a dedicated app, paper that you can flip through and compare with the previous week makes it easier to notice changes. If you use one ring-bound weekly planner with a grid for a one-week overview, dedicated to investment, checking these 7 items becomes a habit.

The market isn't kind, but it is fair. The same disclosures, the same PDFs, and the same financial results are placed in front of everyone. The only difference is the order in which you look at them.

🧊 Summary

I'll put the numbers here one more time.

・Investment 2,140,850 yen (August 4-6, 2026 / 3 companies) ・Current unrealized gain +
264,000 yen ・Inventory turnover period 146 to 188 days ・Price hike notices reach processing manufacturers 15 to 40 business days after the regulation announcement ・Last year, with the same theme, I bought the material side and lost

1.28 million yen

What goes up with tungsten isn't the mining company. It's "the company that can now sell the inventory it bought while it was cheap at a high price". This one line is everything for this time.

How many days is the inventory turnover period for the related stocks you have on hand? Let me know in the comments. If it's under 60 days, you're probably heading in the wrong direction.

Do one thing right now. Tonight, open the financial results of the processing manufacturer you're targeting, pick out the "Inventories" from the balance sheet and the "Cost of Sales" from the income statement, and divide them. Just by doing that, you'll be able to state your position on this theme with numbers. On the morning the next regulation news comes out, that difference will be the difference in timing for entry. The window is only open for a maximum of two weeks.

※This article provides information based on the author's experience and research and does not guarantee specific investment, tax-saving, or profit results. Please make final decisions at your own risk.

【Source List】
・Ministry of Commerce of the People's Republic of China: Export Control Announcements
・Ministry of Economy, Trade and Industry: Mineral Resources Policy / Rare Metal Stockpiling System
・JOGMEC: Metal Resource Information (Tungsten Supply and Demand Report)
・Fuji Die, Dijet Industrial, Nissin Tool: Respective Financial Results and Securities Reports
・Japan Cemented Carbide Tool Manufacturers' Association: Production Dynamics Statistics

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If you've read this far, look at your own account's profit and loss before you press the like button. We can talk after that.
If this note was still helpful, please like and follow. The record continues calmly.

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・[Pre-market Memo] 3 sectors to buy on high oil prices, capturing dividends
・[Live Ammo] 3 lagging defense-related stocks, revealing all numbers for the 1.87 million yen investment
・[Pre-market Memo] Trump's 13.3% tariff, it's not just auto stocks that will fall

#Money #Investment #JapaneseStocks #AssetManagement #HighDividendStocks #FIRE #RareMetals #Tungsten #CementedCarbideTools #ThinkingAboutMoney