Theme 3 · Market Restructuring
Why this theme exists
On 4 April 2022, the Tokyo Stock Exchange replaced its four legacy segments (1st Section, 2nd Section, Mothers, JASDAQ) with three new ones (Prime, Standard, Growth). The reform was not cosmetic — it converted Code obligations from "applies to anyone listed" to "applies most stringently to Prime." From that moment, an IR rep's strategic options have been shaped by which segment the company lists on, what the tradable‑share ratio says about the cap table, and what the transitional measures or improvement period mean for the IR programme.
Theme 3 makes the segment architecture intuitive. By the end you will:
- Know each segment's criteria — market cap, tradable share threshold, governance, English disclosure.
- Understand the tradable‑share ratio — the one mechanic that has reshaped Japanese cross‑shareholding strategy more than any other.
- Read the March 2025 transitional‑measures cliff correctly — including the improvement‑period decision tree.
- Decode TOPIX 2.0 — Phase 1 (Oct 2022 to Jan 2025) and Phase 2 (Oct 2026 to Jul 2028) — and what it means that index inclusion is now decoupled from segment.
- See the 2030 Growth Market cliff coming — and the three exit options (M&A, transfer to Standard, voluntary delisting) for the ~200 affected companies.
The arc in one sentence
April 2022 created the segments; March 2025 was the first enforcement cliff; October 2026 starts the TOPIX selectivity Phase 2; and 2030 closes the Growth Market loophole — so a competent IR rep should treat the reform as a five‑phase programme, not a one‑off relabel.
Posts in this theme
| # | Title | Visual |
|---|---|---|
| 3.1 | From Four Segments to Three: the April 2022 restructuring | Segment migration sankey |
| 3.2 | The Tradable‑Share Ratio | Old vs new tradable‑share definition table |
| 3.3 | The March 2025 Cliff | Improvement‑period decision tree |
| 3.4 | TOPIX 2.0: from census index to selected universe | Phase 1 / Phase 2 timeline |
| 3.5 | The Growth Market's 2030 Cliff | Old vs new criteria + three exit options |
Reading order
Linear (3.1 → 3.2 → 3.3 → 3.4 → 3.5) is recommended. 3.1 sets the architecture; 3.2 zooms in on the binding criterion that surprises most IR teams; 3.3 explains the first cliff; 3.4 explains the index consequence; 3.5 looks at the next cliff.
What you carry into Theme 4
- A clear mental model of who is on Prime / Standard / Growth and why.
- Sensitivity to tradable‑share ratio as the most pressure‑creating number for IR teams with founder, family, or cross‑held stakes.
- The realisation that the reform is not over — every IR strategy from here on must anticipate ongoing structural change.
- An entry point to Theme 4: the March 2023 cost‑of‑capital request was the Follow‑up Council's first big follow‑on enforcement after the April 2022 segment launch.
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