SoftBank Group · 9984.T · Pro forma look-through

What is SoftBank
actually worth?

A dated, assumption-aware sum of the parts. Public stakes use Aug 27, 2026 market data; private assets and post-quarter debt stay editable.

Estimated NAV¥58.20T10,212 yen / share

Market cap¥29.63T9984.T × 5.699B shares

Discount to NAV49%Market says: haircut

Look-through EV¥49.12TMarket cap + modeled net debt

HISTORY / SINCE OPENAI

The NAV gap

Daily market cap versus SoftBank's quarterly reported NAV, with the OpenAI capital events layered on top.

Current discount49.1%Aug 27, 2026

Widest discount68.1%Apr 2025

Change since first check-9.1%Percentage points

August 27, 2026Estimated NAV ¥58.20TMarket cap ¥29.63TDiscount 49.1%

OPENAI CAPITAL TIMELINE

Cash events are shown separately from valuation marks; a new investment adds an asset and, when debt-funded, an offsetting liability.

Sep 30, 2024

Initial investment

$0.5B invested$157B post-money

SVF2 entered OpenAI's September 2024 funding round.

Jan 31, 2025

Secondary purchase

$1.5B invested$157B reference

A secondary purchase followed the initial investment; SoftBank later reported $2.2B invested in FY2024.

Apr 15, 2025

2025 first close

$7.5B net to SBG$260B pre-money

First close of the $40B round after $2.5B was syndicated to co-investors.

Dec 26, 2025

2025 second close

$22.5B invested~11% ownership

The March 2025 commitment was fully funded; SoftBank disclosed an approximately 11% stake.

Feb 27, 2026

New follow-on signed

$30B commitment$730B pre-money

Three $10B tranches were scheduled for April, July and October 2026.

Apr 1, 2026

2026 tranche one

$10B invested$730B pre-money

The first tranche was funded with $10B of bridge borrowing.

Jul 1, 2026

2026 tranche two

$10B invested$730B pre-money

The second tranche was funded with another $10B of bridge borrowing.

Oct 1, 2026

2026 tranche three

$10B planned~13% pro forma stake

Scheduled third tranche; timing may accelerate if OpenAI lists.

How to read it. Official NAV is reported quarterly, so the line between reporting dates is interpolated for orientation, not presented as a daily SoftBank disclosure. Market cap is daily, using split-adjusted 9984.T prices and reported quarter-end share counts. The latest segment connects the March 2026 official NAV to this dashboard's Aug. 11, 2026 snapshot model.

01 / ASSETS

Sum of the parts

Gross holdings¥77.68T

ArmARM

¥36.82Tsnapshot

OpenAIPolymarket / NPM

¥18.85Tmarket

Other holdingsestimate

¥4.91Testimate

SoftBank Corp.9434.T

¥4.54Tsnapshot

SB Energyestimate

¥3.83Testimate

SVF1reported

¥3.60Treported

SVF2 ex OpenAIestimate

¥3.05Testimate

LatAm Fundsreported

¥1.00Treported

DigitalBridge + ArcLightpro forma

¥0.81Tpro forma

T-MobileTMUS

¥0.28Tsnapshot

Method. Arm, SoftBank Corp. and T-Mobile are indexed from SoftBank’s June 30, 2026 gross holding values using Aug 27, 2026 snapshot prices; USD holdings also roll with the captured USD/JPY rate. Aggregates remain at reported or estimated marks.

02 / CAPITAL STRUCTURE

Debt, without the fog

Modeled LTV25.1%

Reported SBG net debt¥10.81TJun. 30, 2026 · SoftBank methodology

Asset-backed financing¥4.68TArm, SBKK and T-Mobile financing

OpenAI follow-on¥3.19T$10B July funded + $10B October planned

DigitalBridge + ArcLight¥0.81TAssumes purchase price is debt-funded

Modeled net debt¥19.48TQuick-and-dirty, pro forma

Gross assets¥77.68T

Debt−¥19.48T

READ THIS FIRST

Useful, directional,
not accounting.

OpenAI. The 13% default is pro forma for SoftBank’s announced $30B 2026 follow-on. Change the stake if you want a current-close rather than fully funded view.

SB Energy. The $40B equity value and 60% SoftBank ownership are base-case assumptions. The IPO filing does not yet specify a price range, share count or final post-offering ownership.

DigitalBridge. Uses SoftBank’s $4B announced enterprise value plus ArcLight’s $650M base and full $400M earnout. It is also added to debt in the pro forma base case.

Debt. This bridges from SoftBank’s adjusted net debt, adds back asset-backed financing so gross assets are comparable, then layers announced commitments. Cash flows, asset sales, tax and financing mix are not modeled.

ARM EXCLUSION / LONG-SHORT LAB

Own SoftBank.
Remove Arm.

SFTBY and ARM trade during the same U.S. session. The chart fits six months of synchronized adjusted close-to-close returns, while the larger hedge ratio removes the look-through value of SoftBank's Arm stake at the Aug 27, 2026 snapshot.

Look-through neutral1.24×ARM short per $1 long SFTBY

6-month beta hedge0.70×125 aligned U.S. sessions

Daily variance explained54%R² of SFTBY returns on ARM returns

Long SFTBY notional

≈ 6,112 SFTBY ADRs at $16.36

For excluding the asset

Valuation hedge

Short $124,243 ARM≈ 496 ARM shares

Matches the snapshot Arm stake value against SoftBank's equity market value. This is the cleaner starting point for “everything except Arm.”

For reducing realized volatility

Regression hedge

Short $70,187 ARM≈ 280 ARM shares

Minimizes historical daily spread variance. It leaves economic Arm exposure because the stock has passed through less than the full stake value.

OPENAI PASS-THROUGH TEST

Does the 60% short make the residual an OpenAI bet?

Mostly an Arm beta hedge, not a pure carve-out. Set the ARM short and a hypothetical OpenAI listing value; the table shows the return on the capital left after the short, assuming other SoftBank assets and ARM are unchanged.

ARM short per $1 long 0.60×OpenAI listing value $1.70T

ARM beta removed85%0.10× daily beta remains

OpenAI stake uplift$103B¥16.39T at 13% ownership

Pass-through needed to double72%on 40% net capital

Current market / NAV+70.4%51% pass-through · residual return

75% value pass-through+103.7%75% pass-through · residual return

100% value pass-through+138.3%100% pass-through · residual return

Read-through. At today's $909B NPM mark, a $1.70T listing adds $103B to SoftBank's pro forma stake. A 0.60× ARM short removes about 85% of observed ARM beta, but 46% of daily SFTBY variance was not explained by ARM and the residual still contains debt, SBKK, funds, energy and other holdings. The doubling case therefore depends on at least 72% of the OpenAI uplift reaching SoftBank's market cap, versus today's 51% market-cap/NAV multiple. History does not guarantee that pass-through. Returns use net notional, not broker margin capital.

DAILY RETURN FITARM explains 54% of SFTBY variance

2026-02-27 → 2026-08-27

60-DAY ROLLING BETA0.60–0.80 range

Latest 0.60

Interpretation. The 0.70× beta hedge is an OLS fit of synchronized daily log returns; the five-session estimate is 0.72×. R² means variance explained, not that ARM caused exactly that percentage of every move. The 1.24× valuation hedge can exceed 1× because SoftBank's Arm stake is worth more than SoftBank's own market capitalization. Rebalance as prices, ownership and the NAV discount change. Borrow cost, ARM dividends, SFTBY's OTC spread, taxes and execution slippage are excluded.