A technology investment firm founded by Brad Gerstner, with offices in Menlo Park and Boston, that manages funds investing in public and private markets, including large AI and cloud positions.
Japanese multinational holding company and investment conglomerate that owns major stakes in telecom, semiconductor design (Arm), and AI infrastructure/data centers, and runs the Vision Fund venture investment arm.
The Verdict: Altimeter Capital vs SoftBank
Both make concentrated bets on AI, but they are different kinds of investor. Altimeter Capital is an SEC-registered adviser managing outside money: its March 2026 Form ADV reports $18.75 billion of regulatory assets across 36 accounts in public and private funds. SoftBank Group is a Tokyo-listed holding company that invests its own balance sheet, through the Vision Funds and direct stakes such as OpenAI and Arm.
The size gap is real but easy to overstate. SoftBank's first Vision Fund alone launched with $93 billion in 2017, about five times Altimeter's current regulatory assets. The more useful comparison is how each one concentrates: Altimeter through a short list of public AI and cloud stocks, SoftBank through a few very large single positions.
Where they compete
Late-stage AI companies and the AI compute supply chain. Altimeter's 13F for June 30, 2026 lists Nvidia ($1.88 billion), Cerebras ($1.60 billion), Meta ($763 million), TSMC ($683 million), CoreWeave ($605 million), and Arm ($582 million) among its largest US-listed holdings. SoftBank is Arm's controlling shareholder, per Arm's SEC filings, and completed its $6.5 billion all-cash acquisition of chip designer Ampere Computing on November 25, 2025. Both, in other words, own pieces of the same AI hardware stack, and both write large checks into frontier AI.
Where they differ
Whose money. Altimeter, founded by Brad Gerstner in Boston in 2008 per Bloomberg, invests for clients: its Form ADV lists 36 accounts, all discretionary. SoftBank invests its own capital, so its shareholders carry the gains and losses on stakes like OpenAI and Arm directly.
Concentration. Altimeter's 20 disclosed public positions were worth $9.83 billion at June 30, 2026, and the top two, Nvidia and Cerebras, made up about 35% of that. SoftBank's concentration is on single companies. By the end of 2025 it had invested about $34.6 billion in OpenAI for roughly an 11% stake, making it the company's third-largest shareholder, per CNBC.
Disclosure. Altimeter's holdings come from quarterly 13F filings, which cover only US-listed long positions, and its annual Form ADV. SoftBank reports quarterly as a listed company; its next earnings briefing, for Q2 of fiscal 2026, is set for November 10, 2026.
For founders: who to pick
Pick Altimeter if you want a growth investor that keeps holding after an IPO. Its public book includes companies such as Snowflake, Uber, and Cerebras, and the firm says it runs "a variety of funds that invest in the public and private markets."
Pick SoftBank if you need a check large enough to change a market, as with OpenAI or Ampere, and can accept a single dominant shareholder with its own balance-sheet priorities.
How to read the numbers
Altimeter's $18.75 billion is SEC regulatory assets under management, a regulatory measure reported in its Form ADV filed on March 31, 2026. Its $9.83 billion 13F figure is a narrower snapshot of US-listed shares held on June 30, 2026, and excludes private holdings. SoftBank's figures are on a different basis: committed capital at a fund's launch ($93 billion for Vision Fund 1), cumulative investment in one company (about $34.6 billion in OpenAI), and acquisition prices ($6.5 billion for Ampere). Comparing any of these directly as "fund size" will mislead.
Frequently asked questions
How big is Altimeter Capital?
Altimeter's Form ADV, filed as an annual amendment on March 31, 2026, reports $18.75 billion of regulatory assets under management across 36 accounts. Its 13F for June 30, 2026 lists 20 US-listed positions worth $9.83 billion, led by Nvidia at $1.88 billion.
Is Altimeter Capital a venture capital firm?
Not purely. Altimeter says it manages "a variety of funds that invest in the public and private markets." It holds large public positions such as Nvidia, Meta, and TSMC alongside private growth investments, and its principal office is at 2550 Sand Hill Road in Menlo Park, California, with a second office in Boston.
What is SoftBank's biggest AI bet?
OpenAI. By the end of 2025 SoftBank had invested about $34.6 billion in OpenAI for roughly an 11% stake, making it the third-largest shareholder, per CNBC. It is also the controlling shareholder of chip designer Arm and bought Ampere Computing for $6.5 billion in cash in November 2025.
Is SoftBank's Vision Fund bigger than Altimeter?
Yes. SoftBank's first Vision Fund launched in 2017 with $93 billion of capital, per CNN, about five times Altimeter's $18.75 billion of regulatory assets in March 2026. The figures are measured differently, though: committed capital at launch versus regulatory assets under management today.
Sources
- Altimeter Capital Management Form ADV, annual amendment (Mar 31, 2026)
- Altimeter Capital 13F-HR for quarter ended Jun 30, 2026 (cover)
- Altimeter Capital 13F-HR information table, Q2 2026
- Altimeter Capital website (offices, strategy)
- Altimeter founding, 2008 (Wikipedia, citing Bloomberg)
- SoftBank Vision Fund $93B and OpenAI stake (Wikipedia, citing CNN and CNBC)
- SoftBank Group to acquire Ampere Computing for $6.5B (press release, Mar 2025)
- SoftBank completes Ampere acquisition (press release, Nov 26, 2025)
- Arm Holdings annual report naming SoftBank as controlling shareholder (SEC)
- SoftBank Group investor presentations (Q2 FY2026 briefing date)
Data from Value Add Pulse coverage and company research — see the full threads for Altimeter Capital and SoftBank.