Share buybacks: Pantheon lifts NAV per share by 1.78%, the other four by less than 0.6%

When a holding company buys back its shares below NAV, the shareholder who stays owns a slightly larger slice of the portfolio. Between 1 July and 9 October 2026, five companies followed by Opulion did just that, with gains ranging from 0.30% to 1.78% per remaining share. Pantheon International tops the range after spending £102.8m, while Prosus manages 0.53% with €1.12bn: how much of the capital is bought back counts as much as the discount paid.

Our analysis of 10 October took the mechanism apart with a fictional example: buying back 10% of the shares at 30% below NAV raises the value of each remaining share by 3.33%. Here we apply it to the five programmes under way, from 1 July to 9 October (from 23 September for Exor), using each company's own filings and the NAV it calculates itself.

Two numbers decide the gain

One measures quantity: the share of capital bought back, meaning the shares taken out of circulation as a proportion of those outstanding at the start of the period. The other measures price: the discount paid, the gap between the average buyback price and NAV per share, itself the estimated value of the portfolio net of debt, divided by the number of shares.

The gain for the remaining shareholder is roughly the product of the two, divided by the share of stock that remains. Buying back 5% of the capital at 20% below NAV adds about 1.05% to each remaining share. At 1% of the capital and a 50% discount, the uplift falls to about 0.51%. A discount two and a half times deeper does little to offset a quantity five times smaller.

The chart below ranks the five companies on this basis. Three profiles emerge: Pantheon combines both numbers, Scottish Mortgage buys a lot at a small discount, Exor pays the deepest discount on a small quantity.

Pantheon International: volume and discount combined

Pantheon International, a London-listed private equity investment company, bought back 26.27 million shares between 1 July and 9 October, for about £102.8m, or 6.58% of the shares outstanding at 30 June. It paid an average of 391.43 pence, against an average NAV of 523.30 pence, the latest published at the time of each purchase: a discount of 25.2%. All shares bought back are cancelled.

The result is a gain of +1.78% of NAV per share, and the company's own figures allow a cross-check. Pantheon reports the average discount on its buybacks every month: 24.9% in July and 23.7% in August, against 24.86% and 23.70% on our method. The company also puts the buyback contribution to its NAV per share at 2.4 pence in July and 2.6 pence in August, about 0.5% a month, against 0.44% and 0.52% on our formula.

That pace is funded by a disposal: announced on 12 May and completed at 30 June, the sale of positions in 42 funds raised £224m net, at least 80% of which, about £180m, is earmarked for buybacks, as our analysis of 10 October set out. One caveat: at 31 August, 74% of the portfolio valuations still dated from 30 June. The gain is thus measured against an estimated NAV, which future disposals will put to the test.

Scottish Mortgage: plenty of shares, little discount

Scottish Mortgage bought back 53.05 million shares, 4.84% of the shares outstanding at 30 June, excluding treasury shares, for about £780m. Only Pantheon retired a larger share of its capital. Yet the Baillie Gifford-managed trust trades close to NAV: it paid an average of 1,470.63 pence, against an average NAV of 1,603.25 pence on the day of each purchase, a discount of 8.3%. The gain comes to +0.42% per share.

The NAV used values the trust's debt at fair value, as in the company's monthly factsheet. With debt at par, the discount falls to 6.2% and the gain to 0.32%.

The shares bought back are held in treasury, that is, by the company itself, and can be reissued. Scottish Mortgage did so in the spring: 34.8 million shares put back on the market from 5 May to 2 June 2026, at a premium to NAV. The mechanism works both ways: buy below NAV, sell above it.

Exor: the deepest discount, in just thirteen sessions

On 22 September Exor announced a €500m programme, and the next day launched a first tranche of up to €125m, to be completed by the end of November. In thirteen sessions from 23 September to 9 October, the holding company bought back 1.09 million shares for €76.2m, at an average of €70.05, against a last published NAV of €157.9 per share at 30 June. The discount paid comes to 55.6%, the deepest in the sample.

Those 1.09 million shares represent only 0.54% of the shares outstanding, however, and the gain is limited to +0.30% per share. Exor calculates its NAV per share excluding treasury shares, so the effect shows up in its own measure as soon as the shares are bought. The programme aims to reduce the share capital, with no cancellation date set so far.

As a hypothesis, if the full €500m were spent at the same average price and against the same NAV, Exor would withdraw 3.52% of its shares outstanding at 30 June and the gain would be about 2.0% per share. This is a sensitivity: the share price and NAV will move before the programme ends.

GBL: a gain deferred until cancellation

GBL bought back 1.77 million shares for €131.9m from 1 July to 9 October, at an average of €74.60, or 1.48% of the shares outstanding at 30 June. Against the NAV of €100.77 per share published at 30 June, the average price implies a discount of 26.0% and a gain of +0.39% per share.

GBL's accounting method defers this gain. Its NAV includes treasury shares, counted at their market price, and is divided by all issued shares, treasury shares included. When the shares are bought, the published NAV per share stays put: cash goes out, treasury shares come in for the same amount. The effect appears when the general meeting cancels the shares. Calculated on shares outstanding only, NAV at 30 June comes to €102.58 per share and the gain to 0.41%.

At 9 October, GBL held 12.06 million treasury shares, 9.3% of its issued capital, and had executed 73.1% of its eighth €500m programme. A minority of these shares may go to incentive plans rather than cancellation. For GBL shareholders, the cancellation date matters as much as the pace of buying.

Prosus: the biggest cheque, for 1.41% of the capital

Prosus bought back 29.77 million shares for €1.12bn over the period, at an average of €37.76 against NAV per share of €59.98 at 30 June: a discount of 37.1%. Those shares represent 1.41% of the shares counted in NAV, and the gain comes to +0.53% per share, or 0.55% using NAV at 30 September, €61.30.

In absolute terms, though, Prosus makes the largest transfer in the sample: about €660m of NAV passed on to the remaining shares. Spread across NAV of about €127bn at 30 June (Prosus NAV file), it translates into only a modest effect per share. The shares bought back go into treasury and are then cancelled in batches.

For every 100 spent, what goes to those who stay

A second calculation isolates how hard each euro, or each pound, works. A company that spends 100 buying back its shares below NAV retires shares that were worth more than that in NAV terms, and the difference accrues to the remaining shareholders. It equals 100 × discount ÷ (1 − discount), and depends on the discount alone.

Exor gets the most out of each euro: for every €100 spent, about €125 of NAV passes to the remaining shareholders. Despite spending 42% less than GBL over the period, it passed twice as much NAV on to its remaining shares, about €96m against €46m. But its NAV of €32bn, nearly two and a half times GBL's, shrinks that transfer to 0.30% per share.

Every board has to make this trade-off. Each euro spent on buybacks is a euro less for investment or debt repayment. The deeper the discount, the more NAV a buyback delivers immediately, and the higher the bar for a new investment paid at full value.

The next tests

At the end of October, if the usual timetable holds, Pantheon's monthly update to 30 September will give the average discount on September buybacks. GBL's buyback mandate runs to 6 November: its extension and the cancellation date of treasury shares will show when the gain enters the published NAV. Exor expects to complete its first tranche of up to €125m by the end of November, 61% executed at 9 October and 87% at 16 October, as our brief of 19 October showed. For shareholders in each of these holding companies, the gain will show in the next NAV per share, after costs and, at GBL, after cancellation.

How we counted

Period: 1 July to 9 October 2026, except for Exor, whose purchases begin on 23 September. Quantities and amounts come from each company's filings: weekly reports from GBL and Exor, daily notices from Scottish Mortgage and Pantheon International published on Investegate, and Prosus's daily programme file. For Scottish Mortgage and Pantheon, the amount is the sum of quantities multiplied by the prices published each day.

Share bought back: shares bought divided by shares outstanding at 30 June, excluding treasury shares. Discount: 1 minus the average price divided by the reference NAV per share. Gain: share × discount ÷ (1 − share). The formula treats purchases spread over time as a single transaction and ignores costs and taxes. It gives an order of magnitude. NAV transfer: shares bought × (NAV per share − average price).

Reference NAV: the 30 June figure published by GBL (€100.77), Exor (€157.9) and Prosus (€59.98). For Scottish Mortgage, NAV on the day of each purchase, with debt at fair value, weighted by volume. For Pantheon, the last NAV published at the time of each purchase, the method the company uses for its own average discount. The 30 June NAVs are more than three months old: the discount on the day of each purchase may differ from our measure, in either direction.

Variants: GBL on shares outstanding only, 0.41%. Scottish Mortgage with NAV at 30 June, 0.45%, or with debt at par, 0.32%. Pantheon with NAV at 30 June, 1.80%. Prosus with NAV at 30 September, 0.55%. Opulion hypothesis for Exor: €500m at the average price of €70.05, or 7.14 million shares and 3.52% of shares outstanding at 30 June. Each gain is measured against its own company's NAV, and the gains do not add up from one holding company to another.