New research · Now available

The Corestar Index
for the FTSE 350

Behaviour determines how well a company executes. Corestar measures it. This paper shows where friction is hiding across the FTSE 350, what it costs, and which leaders are pulling ahead.

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Introducing Corestar

Corestar in two minutes.

The launch

Rory Sutherland on Corestar.

Rory Sutherland interviewed by Guy Lambert at the launch of Corestar, hosted by Page Executive in September.

The Corestar CEO Index

How Britain’s CEOs rank.

Ninety-nine FTSE 350 leaders, ranked by Stabilisation Efficiency: the friction they remove, set against the difficulty of the seat they inherited.

The Corestar Index · top 5 of 99Seat difficulty scored 0 to 10

The Corestar Index top 5, ranked by Stabilisation Efficiency then by seat difficulty. Seat difficulty is scored 0 to 10. Load is the pressure the organisation carries.
Rank	Company and chief executive	Seat difficulty	Stabilisation Efficiency	Load	Band
1	Next Simon Wolfson General retail · FTSE 100	4.9	0.40	2.5	Star
2	LondonMetric Property Andrew Jones REITs · FTSE 100	4.8	0.40	2.4	Star
3	Rolls-Royce Tufan Erginbilgic Aerospace & defence · FTSE 100	7.5	0.53	4.7	System Calmer
4	Endeavour Mining Ian Cockerill Mining · FTSE 100	7.3	0.53	4.6	System Calmer
5	Costain Group Alex Vaughan Construction & materials · FTSE 250	6.3	0.53	4.0	System Calmer

Seat difficulty is the difficulty of the job each leader inherited, so a high seat difficulty at a low SE is a leader running a hard job calmly. Source: The Corestar Index for the FTSE 350, White Paper 3, September 2026.

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From the launch event

What people say about Corestar.

Ben Kumar, 7IM
What brought you to this Corestar event?

Caroline Johnson, The Business Model Company
Why is Corestar compelling?

Emily Carr-Bennett, Saatchi & Saatchi
What interests you in Corestar?

Three questions. One instrument.

For Business Leaders

Will your strategy survive the reality of your culture?

Corestar reveals the behavioural forces shaping your performance, so you can harness your company’s true strength.

Find your true strength

For Executive Search

Is your candidate making their business easier to run, or harder?

One context-adjusted number that separates the leader from the circumstances they inherited.

De-risk the appointment

For Investors & PE

Does the culture add to the price, or subtract from it?

Leadership effect, measured discreetly from public signals. No management access required.

Price the leadership effect

By introduction

Corestar works with a small number of boards, search firms and investors at any one time. If the questions above are your questions, we should talk.

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