Why Japanese IPOs come in lots of 100 shares

You cannot buy one share

Japanese IPO applications are always in units of 100 shares. There is no way to apply for one share, or for fifty. If the offer price is 1,000 yen, the smallest possible application is 100,000 yen.

For anyone used to a market where you can buy a single share, or even a fraction of one, this is the first real barrier. It is not a rule of this site or of any particular broker — it is how the market itself is built.

Where the 100-share unit comes from

Japanese shares trade in a fixed lot called the trading unit. Companies used to set their own — some at 1,000 shares, some at 100, some at 1 — which made the market confusing to navigate. The exchange standardised all listed companies to 100 shares in October 2018.

So the unit is not something the listing company chose, and not something your broker can waive. Every listed company in Japan uses the same 100.

But some brokers sell single shares — why not for IPOs?

Several brokers do offer fractional trading, letting you buy fewer than 100 shares of an already-listed company. That is a service the broker runs on the secondary market: it buys full lots and splits them among customers afterwards.

An IPO allocation is different. The shares are being distributed by the underwriting syndicate before trading opens, in the units the offering specifies, and the offering specifies 100. There is no mechanism to split an allocation, so fractional services do not apply to IPO applications at any broker.

You can, of course, buy a single share of the company after it lists. But that means buying at the market price on day one — which is precisely the price you would have been selling into, not the offer price you were hoping to be allocated at.

What this actually costs you

Across the 65 companies that listed in 2025 — the most recent full year — the cash required ranged from about 21,000 yen to about 452,000 yen, with a median around 130,000. About one in three could be applied for with 100,000 yen or less.

So the barrier is real but not uniform. Cheaper listings appear most months, and the cost is decided entirely by the share price rather than by the size or quality of the company.

What to do if your capital is limited

Use brokers that require no deposit before you apply. Since you only pay after winning, the 100-share minimum stops being money you must set aside in advance and becomes money you need only if you actually get an allocation. That single change does more for a small account than anything else.

Favour brokers with a fully equal draw. Where the lottery is weighted by how many shares you applied for, the 100-share minimum puts you at the bottom of the weighting. Where every applicant gets one ticket, applying for the minimum costs you nothing in odds.

Choose the cheaper listings while you are building up. A 23,000-yen listing and a 390,000-yen listing each give you one entry in an equal draw. The cheaper one is not a worse lottery ticket.

One thing not to do

Do not stretch to apply for a listing you could not comfortably pay for. Winning is binding at most brokers, and declining after a win carries a penalty at several of them — typically a month of being blocked from applying, sometimes voiding your other pending applications.

Apply only within what you could pay if every application you have running happened to win at once. That is the number that matters, not the cost of any single one.