About Capacity Letter
Industrial materials — what they do, how they are made, who supplies them.
I'm Robin Wen. Capacity Letter is a reference on industrial materials: the grades that actually get sold, the process steps that decide them, and the countries and companies that hold the capacity.
I'm an independent analyst — not a reporter with a beat, and not a columnist for a side. The method is simple even when the subject isn't: read the actual sources, then work out what they mean. Filings, earnings calls, policy documents, statistics, reporting in more than one language. After that comes the only part I'm really here for — say what I think, plainly, and leave it on the record where it can be checked.
The guides are built to be used, not skimmed: a grade sheet, a list of applications, a supplier map, and the primary documents behind each claim. Judgment is still here — it sits inside the guides, where it can be checked against the sources, rather than standing alone as a take.
Every guide answers three questions
Same three, in the same order — because a grade means nothing until you know the process and the supply behind it.
Grade
What exactly is being sold?
Four nines and seven nines are two different trades. One code can carry different numbers. Before a figure means anything, you need to know what it measures.
Process
How is it made?
Gallium is a by-product of alumina refining; tungsten is pressed, not poured; refining is an industry of its own. The process sets which grade you can even be offered.
Supply
Who holds it, and what gates the sale?
Where the tonnage comes from, which licences gate the sale, and where recycling only postpones the dependency. Countries decide supply more than companies do.
How a long-form piece works
The pieces on the blog: an event, the sources underneath, then a judgment. The guides above are built differently — definition, process, supply, and what the paperwork actually proves.
Something that happened
An event, not a roundup: a tariff, a plant opening, an earnings call, a document. When several things point the same way, I say so.
Primary sources
The filings and sources underneath, in whatever language they were written in. Numbers get sources, not vibes.
A judgment
Stated plainly and on the record. When I'm wrong, I correct it in the open rather than quietly deleting the post.
What this is not
Not investment advice
No price targets, no buy calls, no portfolio recommendations. Everything here is analysis, not advice — see thedisclaimer.
Not a news wire
The news is usually where a question starts. The page is then built from the source documents and the numbers, not from somebody else's headline.
A note on the name
I write under a pen name, because I'd rather the argument be judged on its merits than on my résumé. Read the method above, check the sources, and judge the output.
Corrections are published, not hidden. If you think I've got something wrong, tell me.
Judge the argument by the work, not the bio.