The Corestar CEO Index

One definitive number.

Stabilisation Efficiency reveals whether a leader adds to performance or creates friction, shown here across the FTSE 100 and 250.

The cohort

How Britain’s CEOs measure up.

FTSE 100 & 250 chief executivesSE · lower is better
0.600.750.921.151.20typical CEO · 0.87
Stabilisation Efficiency bands for the FTSE 100 & 250 cohort
Share of cohortBandSE rangeWhat it means
0%The Rare EliteSE below 0.75Definitive value-add. Rarely the loudest names in the press.
0%The Competent CoreSE 0.75 – 0.92The typical CEO scores around 0.87: modestly value-adding, not transformational.
0%The Friction AddersSE 0.93 – 1.15Roughly one in seven score above par, potentially consuming value rather than creating it.
0%Insufficient TenureLow confidenceNot yet in post long enough to judge. We say so, rather than guess.

How the number is made.

These metrics resolve into a single, definitive number we call Stabilisation Efficiency (SE), which answers one question: to what extent is this leader enhancing business performance? The methodology works in three steps.

Measure the environment first

Every sector and every business carries its own inherent load: structural complexity, market uncertainty, legacy issues. We establish this baseline before assessing the leader, so the context is never mistaken for the person.

Isolate the leader’s effect

We then measure what the leader personally brings: their execution energy, their openness to feedback, their impact on alignment and conviction. The SE score is the relationship between the two: the load the organisation actually carries under this leader, versus the load its environment would predict.

Band and weight the result

Scores are calibrated against a demanding benchmark. Leaders are paid to add value, so par is set as a slight enhancement to business performance. Every assessment carries a Confidence Band (High, Medium or Low) based on evidence consistency and tenure, so a promising score never masquerades as a proven track record.

Judged on the reality they were handed.

Corestar distinguishes a leader steering through a collapsing market from one who is simply struggling. Because every SE score is environment-adjusted, a candidate who previously managed a troubled operation is judged on the situation they inherited, not against an impossible ideal.

This insight is available for CEOs and for C-Suite candidates.

September 2026

The next iteration of the CEO Index will be revealed.

Ask for early sight

Questions, answered.

What is Stabilisation Efficiency?

Stabilisation Efficiency (SE) measures a leader's capacity to reduce friction inside an organisation. It is derived from public signals, adjusted for the environment the leader inherited, and independent of share price and other lag indicators.

Does Corestar need access to the company or its management team?

No. Stabilisation Efficiency is derived entirely from public signals and requires no management access, no questionnaires and no footprint inside the target.

How is the SE score calculated?

In three steps: first, the inherent load of the sector and business is measured, so context is never mistaken for the person. Second, what the leader personally brings is isolated: their execution energy, openness to feedback, and impact on alignment. The SE score is the relationship between the two.

Is a leader judged against every other leader on the same terms?

No. Every SE score is environment-adjusted. A candidate who previously managed a troubled operation is judged on the situation they inherited, not against an impossible ideal.