# AI investors based in Boston (2026 list) > 70 AI investors based in Boston, 89% active in the last 12 months. Led by MassChallenge, Battery Ventures, Polaris Partners. Ranked by what they funded. Source: https://millionrounds.com/lists/ai-investors-based-in-boston (Millionrounds; every figure on the page links to its filing or article) [Investor Lists](https://millionrounds.com/lists) # AI investors based in Boston Updated 7 November 2026 Firms with an address in Boston that we have watched back an AI company in the last two years. [See all 70 *→*](https://millionrounds.com/login?join=1&next=%2Fapp%2Finvestor-lists%2Fai-investors-based-in-boston)The top 25 **70** investors on the list *+1* this week **634** cheques in 12 months *+0%* against the market **$19M** median round they joined *+138%* against the market median **89%** wrote a cheque in 12 months **60%** have led a round ## The Top 25 Ordered by cheques observed, never by anything anyone paid for Deploying now (24) - 1 [MassChallenge](https://millionrounds.com/fund/masschallenge) *Deploying now* Accelerator · United States **984** **$1.8M** median round **Sept 2026** last seen - 2 [Battery Ventures](https://millionrounds.com/fund/battery-ventures) *Deploying now* VC firm · United States **658** **$32M** median round **Nov 2026** last seen - 3 [Polaris Partners](https://millionrounds.com/fund/polaris-partners) *Deploying now* VC firm · United States **490** **$36M** median round **Oct 2026** last seen - 4 [RA Capital Management](https://millionrounds.com/fund/ra-capital-management) *Deploying now* Private equity · United States **395** **$93M** median round **Nov 2026** last seen - 5 [Summit Partners](https://millionrounds.com/fund/summit-partners) *Deploying now* Private equity · United States **356** **$81M** median round **Oct 2026** last seen - 6 [Wellington Management](https://millionrounds.com/fund/wellington-management) *Deploying now* VC firm · United States **297** **$130M** median round **Oct 2026** last seen - 7 [Globespan Capital Partners](https://millionrounds.com/fund/globespan-capital-partners) quiet VC firm · United States **156** **$43M** median round **Jul 2025** last seen - 8 [406 Ventures](https://millionrounds.com/fund/406-ventures) *Deploying now* VC firm · United States **136** **$15M** median round **Oct 2026** last seen - 9 [Flare Capital](https://millionrounds.com/fund/flare-capital-partners) *Deploying now* VC firm · United States **93** **$12M** median round **Oct 2026** last seen - 10 [HarbourVest Partners](https://millionrounds.com/fund/harbourvest-partners) *Deploying now* Fund of funds · United States **93** **$54M** median round **Jun 2026** last seen - 11 [MassMutual Ventures](https://millionrounds.com/fund/massmutual-ventures) *Deploying now* VC firm · United States **84** **$14M** median round **Oct 2026** last seen - 12 [Pillar VC](https://millionrounds.com/fund/pillar-vc) *Deploying now* VC firm · United States **83** **$8.2M** median round **Sept 2026** last seen - 13 [Castle Island Ventures](https://millionrounds.com/fund/castle-island-ventures) *Deploying now* VC firm · United States **78** **$7M** median round **Oct 2026** last seen - 14 [The E14 Fund](https://millionrounds.com/fund/e14-fund) *Deploying now* VC firm · United States **72** **$8M** median round **Oct 2026** last seen - 15 [One Way Ventures](https://millionrounds.com/fund/one-way-ventures) *Deploying now* VC firm · United States **71** **$8M** median round **Nov 2026** last seen - 16 [PSG](https://millionrounds.com/fund/providence-equity-partners) *Deploying now* VC firm · United States **68** **$50M** median round **Aug 2026** last seen - 17 [Underscore VC](https://millionrounds.com/fund/underscore-vc) *Deploying now* VC firm · United States **65** **$7M** median round **Sept 2026** last seen - 18 [HubSpot Ventures](https://millionrounds.com/fund/hubspot-ventures) *Deploying now* Corporate VC · United States **64** **$25M** median round **Nov 2026** last seen - 19 [Four Cities Capital](https://millionrounds.com/fund/four-cities-capital) *Deploying now* VC firm · United States **62** **$5.3M** median round **Oct 2026** last seen - 20 [Advent International](https://millionrounds.com/fund/advent-international) *Deploying now* Private equity · United States **59** **$740M** median round **Oct 2026** last seen - 21 [Bain Capital](https://millionrounds.com/fund/bain-capital) *Deploying now* Private equity · United States **58** **$50M** median round **Aug 2026** last seen - 22 [Spectrum Equity](https://millionrounds.com/fund/spectrum-equity) *Deploying now* Private equity · United States **55** **$62M** median round **Sept 2026** last seen - 23 [Elephant](https://millionrounds.com/fund/elephant) *Deploying now* VC firm · United States **54** **$16M** median round **Jul 2026** last seen - 24 [Optum Ventures](https://millionrounds.com/fund/optum-ventures) *Deploying now* VC firm · United States **53** **$25M** median round **Oct 2026** last seen - 25 [Glasswing Ventures](https://millionrounds.com/fund/glasswing-ventures) *Deploying now* VC firm · United States **50** **$5.2M** median round **Oct 2026** last seen **45 more on this list** All 70 are in the app, with filters for stage, sector and market. A free account shows 10 per search, Pro up to 1,000. [See the whole list *→*](https://millionrounds.com/login?join=1&next=%2Fapp%2Finvestor-lists%2Fai-investors-based-in-boston) ## The Newest Cheques Rounds this list's investors joined most recently - **5** Nov **[Alethio Therapeutics](https://millionrounds.com/company/alethio-therapeutics)** Series A · $90M *Led by* [RA Capital Management](https://millionrounds.com/fund/ra-capital-management) - **4** Nov **[Shackleton AI](https://millionrounds.com/company/shackleton-ai)** Seed · $5M *Led by* [Battery Ventures](https://millionrounds.com/fund/battery-ventures) - **4** Nov **[Lazarus AI](https://millionrounds.com/company/lazarus-ai)** $43M *With* [One Way Ventures](https://millionrounds.com/fund/one-way-ventures) - **3** Nov **[Traversal](https://millionrounds.com/company/traversal)** Series B · $120M *With* [Battery Ventures](https://millionrounds.com/fund/battery-ventures) - **3** Nov **[Applied Compute](https://millionrounds.com/company/applied-compute)** Other · $350M *With* [HubSpot Ventures](https://millionrounds.com/fund/hubspot-ventures) - **29** Oct **[Crux Labs](https://millionrounds.com/company/crux-labs)** Seed · $6M *Led by* [Misneach](https://millionrounds.com/fund/misneach) ## Stages This Year 596 rounds - Series A **15%** - Other **14%** - Venture **14%** - Seed **13%** - Series B **12%** - Other **32%** ## What They Backed Sectors, last 12 months - AI **220** - Biotech **111** - Healthcare **69** - Pharma **42** - Fintech **33** - Big Data & Analytics **32** ## Cheques by Quarter Led Joined 164 Q1 25 149 Q2 25 154 Q3 25 204 Q4 25 208 Q1 26 161 Q2 26 162 Q3 26 36 Q4 26 The last bar is the quarter still running. ## Lists Like This - [AI investors based in San Francisco 353](https://millionrounds.com/lists/ai-investors-based-in-san-francisco) - [AI investors based in New York 345](https://millionrounds.com/lists/ai-investors-based-in-new-york) - [Seed investors based in San Francisco 273](https://millionrounds.com/lists/seed-investors-based-in-san-francisco) - [Series A investors based in San Francisco 266](https://millionrounds.com/lists/series-a-investors-based-in-san-francisco) - [Series A investors based in New York 255](https://millionrounds.com/lists/series-a-investors-based-in-new-york) - [Seed investors based in New York 227](https://millionrounds.com/lists/seed-investors-based-in-new-york) - [AI investors based in London 223](https://millionrounds.com/lists/ai-investors-based-in-london) - [Series B investors based in New York 198](https://millionrounds.com/lists/series-b-investors-based-in-new-york) - [Fintech investors based in New York 197](https://millionrounds.com/lists/fintech-investors-based-in-new-york) [All investor lists *→*](https://millionrounds.com/lists) ## Quick answers about AI investors based in Boston ### Who are the most active AI investors based in Boston? By cheques observed, the most active are MassChallenge, Battery Ventures, Polaris Partners, RA Capital Management and Summit Partners. ### How many AI investors based in Boston are there? 70 are on record. 89% made an investment in the last 12 months and 60% have led a round. ### Which stages do AI investors based in Boston back? Of the rounds with a named stage in the last 12 months, mostly Series A (22%) and Seed (19%). ### How big are the rounds AI investors based in Boston join? The typical (median) round among the leading investors here is $25M. ### Which sectors do AI investors based in Boston back most? In the last 12 months, mostly AI, Biotech and Healthcare. ### Which AI investors based in Boston lead the most rounds? Battery Ventures (29 led), RA Capital Management (15 led) and Wellington Management (15 led). ### What have AI investors based in Boston invested in recently? Recent rounds include Alethio Therapeutics (Series A, Nov 2026, with RA Capital Management), Shackleton AI (Seed, Nov 2026, with Battery Ventures) and Lazarus AI (Nov 2026, with One Way Ventures). ### How is this list of AI investors based in Boston ranked? By cheques observed, from the rounds and filings we watched, and never by anything anyone paid for. It is rebuilt every night. Built from the rounds we watched, refreshed every night. [How we count](https://millionrounds.com/methodology) · [Report a correction](https://millionrounds.com/corrections)