researchagent
claude-brief-2-fundraisings
raw research doc for brief 2 fundraisings agent. web research by the agent on sept 4 2026.
the 10 largest 2026 funding rounds by accelerator alumni (jan 1 - sep 4, 2026)
scope: rounds announced between january 1 and september 4, 2026 by startups that went through y combinator or a yc-like program (techstars, a16z speedrun, antler, entrepreneur first, south park commons, sequoia arc, pearx, neo, 500 global). "went through" means the founders participated in the program, verified against the program's own company directory or the program's own write-up. companies where a program was merely a seed investor (no program participation) are listed in the candidates table but not ranked.
ranking is by primary equity round size. debt facilities, tender offers, secondary sales, and acquisitions are excluded. every round below has two sources (announcement + independent confirmation) unless marked "single source".
top 10
| rank | company | what it does | program + batch | round | date announced | lead investors | revenue / arr | sources |
|---|---|---|---|---|---|---|---|---|
| 1 | kalshi | cftc-regulated prediction market exchange for event contracts | y combinator, w19 | $1.0b series f at $22b valuation | may 7, 2026 | coatue (lead); sequoia, a16z, paradigm, ivp, morgan stanley, ark invest participating | annualized revenue >$1.5b; annualized volume $178b (company-stated) | techcrunch / pymnts / yc directory |
| 2 | whatnot | livestream shopping marketplace | y combinator, w20 | $545m series g at $20b valuation | aug 7, 2026 | iconiq, lightspeed, avra (co-leads); a16z, greycroft, y combinator participating | revenue not public; $8b gmv in 2025 (company-stated) | tubefilter / quartz / cnbc / yc directory |
| 3 | supabase | open-source postgres backend platform | y combinator, s20 | $500m series f at $10.5b post-money | jun 4-5, 2026 | gic (lead); stripe, georgian, salesforce ventures participating | not public (~10m developers; previous round $100m at $5b in oct 2025) | techcrunch / cnbc / yc directory |
| 4 | replit | ai-powered software creation and deployment platform | y combinator, w18 | $400m series d at $9b valuation | mar 11, 2026 | georgian (lead); g squared, prysm, coatue, a16z, craft, y combinator, accenture ventures, okta ventures, databricks ventures participating | not public in the announcement (third-party trackers cite ~$300m arr; unverified) | prnewswire / built in sf / dealroom / yc directory |
| 5 | astranis | small geostationary communications satellites for commercial and us military customers | y combinator, w16 | $300m series e equity (plus a $155m delayed-draw credit facility from trinity capital; $455m total new capital); $2.8b valuation per payload (single source for valuation) | may 6, 2026 | snowpoint ventures and franklin templeton (co-leads); a16z, blackrock, baillie gifford, fidelity, bam elevate, nimble partners participating | revenue not public; >$1b commercial contract backlog (company-stated) | astranis blog / payload / via satellite / yc directory |
| 6 | exa | web search engine and search api built for ai agents | y combinator, s21 | $250m series c at $2.2b valuation | may 20, 2026 | andreessen horowitz (lead); quantumlight participating (per alleywatch) | not public (5,000+ customers, 400k+ developers) | exa blog / benzinga / alleywatch may 2026 / yc directory |
| 7 | starcloud | orbital data centers (gpu satellites for ai training/inference) | y combinator, s24 | $170m series a at $1.1b post-money | mar 30, 2026 | benchmark and eqt ventures (co-leads); nfx, nebular, y combinator, adjacent, 776, fuse participating | not public (pre-revenue) | businesswire / techcrunch / yc directory |
| 8 | corgi | full-stack ai-native business insurance carrier for startups | y combinator, s24 | $160m series b at $1.3b valuation (largest of three 2026 corgi rounds; see candidates table) | may 6, 2026 | tcv (lead); kindred ventures, leblon capital, first order fund participating | $40m annualized run rate at series a (jan 2026); management target of $450m run rate by end of 2026 (per techcrunch, jul 2026) | techcrunch / the next web / yc directory |
| 9 | hightouch | composable cdp and agentic marketing platform | y combinator, s19 | $150m series d at $2.75b valuation | apr 27, 2026 | growth equity at goldman sachs alternatives (lead); bain capital ventures, iconiq, sapphire, amplify, y combinator, td7 participating | not disclosed in the announcement (yc directory profile states $100m arr as of apr 2026 - single source) | businesswire / hightouch blog / pymnts / yc directory |
| 10 | preply | online language-tutoring marketplace (100k+ tutors, 180 countries) | techstars berlin, 2015 class | $150m series d at $1.2b valuation | jan 21, 2026 | westcap (lead); ebrd, horizon capital participating | revenue not public; company states it became ebitda positive in the prior 12 months | pulse2 / bloomberg / techstars startup profile / kyiv post on the 2015 techstars berlin class |
notes on the ranking:
- hightouch and preply tie at $150m; hightouch is placed first on the higher post-money valuation. either ordering is defensible.
- flock safety (yc s17) was reported by the information in april 2026 to have sold ~$200m of new shares at an $8.4b valuation. this was not company-announced and the lead investor is unknown; it is a single-source report, so it is not ranked. if counted it would sit at #7.
- afterquery (yc w25) closed a series b at a $3.2b valuation on sep 1-2, 2026 (reported by forbes, confirmed by yc's gustaf alstromer), but the round size has not been disclosed, so it cannot be ranked.
- two very large 2026 rounds come from companies where a listed program was an early investor but there is no evidence the founders went through the program: baseten ($1.5b series f, jun 22, 2026; south park commons was the seed investor - spc's own page says the founders "walked into spc" to pitch and spc signed the term sheet the day after incorporation) and lovable ($400m series c, aug 12, 2026; antler calls it a "portfolio company" and was an early backer). both are excluded from the ranking and listed below.
candidates checked
| company | program | 2026 round found | outcome / reason |
|---|---|---|---|
| kalshi | yc w19 | $1.0b series f (may 7) | ranked #1, two sources |
| whatnot | yc w20 | $545m series g (aug 7) | ranked #2, two sources |
| supabase | yc s20 | $500m series f (jun 4-5) | ranked #3, two sources |
| replit | yc w18 | $400m series d (mar 11) | ranked #4, two sources |
| astranis | yc w16 | $300m series e + $155m credit (may 6) | ranked #5 on the $300m equity; valuation ($2.8b) single source |
| exa | yc s21 | $250m series c (may 20) | ranked #6, two sources |
| starcloud | yc s24 | $170m series a (mar 30) | ranked #7, two sources |
| corgi | yc s24 | $160m series b (may 6); also $108m series a (jan 2026), $106m series b1 at $2.6b (may 28), and an undisclosed series b2 at $4b (reported jul 23) | ranked #8 on the largest round; the others are below the cutoff or undisclosed |
| hightouch | yc s19 | $150m series d (apr 27) | ranked #9, two sources |
| preply | techstars berlin 2015 | $150m series d (jan 21) | ranked #10, two sources; program participation confirmed via techstars' own profile and 2015 kyiv post coverage |
| flock safety | yc s17 | ~$200m share sale at $8.4b (apr 2026) | not ranked: reported only (the information, relayed by gurufocus and alleywatch); not company-announced; lead unknown; single source |
| afterquery | yc w25 | series b at $3.2b (sep 1-2); $30m series a at $300m (apr 9) | not ranked: series b size undisclosed; $100m+ annualized revenue at series a (company-stated). yc's fastest-ever unicorn |
| baseten | south park commons (seed investor) | $1.5b series f at $13b (jun 22); $300m series e at $5b (jan 20-23) | excluded: spc invested at incorporation but founders did not go through an spc fellowship/program (spc's own company page). would be #1 if counted |
| lovable | antler (early investor) | $400m series c at $13.3b (aug 12); $500m arr (jun 2026) | excluded: antler describes it as a "portfolio company" / early backer; no evidence founders went through an antler residency. would tie #4 if counted |
| deepgram | yc w16 | $130m series c at $1.3b (jan 13) | below cutoff (#11) |
| avoca | yc w23 | $125m+ series b at $1b (apr 27) | below cutoff |
| zepto | yc w21 | pre-ipo placement of |
below cutoff; round size reported by business standard / newsbytes, not company-announced |
| render | yc s19 | $100m series c extension at $1.5b (feb 17) | below cutoff |
| slash | yc alum (batch not re-verified) | $100m series c (apr 2026, per alleywatch) | below cutoff |
| flutterwave | yc s16 | series e at $3.2b valuation with ripple (jun 16) | not ranked: round size undisclosed |
| eight sleep | yc s15 | $50m at $1.5b led by tether (mar 4) | below cutoff (techcrunch's unicorn list said $150m; crunchbase news, coindesk and hlth all say $50m - used the majority figure) |
| blacksmith | yc alum | $45m series b at $550m (aug 12) | below cutoff |
| harper | yc alum | $47m series a + seed (feb 25) | below cutoff |
| naive | yc alum | $28.5m (aug 6) | below cutoff |
| terminal | yc alum | $20m series a (betakit) | below cutoff |
| genspark | none found | $485m series b extension at $2.6b (jun 17) | excluded: no yc or other listed accelerator affiliation found (techcrunch's unicorn roundup does not claim one; a yc search returned nothing) |
| science corp | none | $230m series c (mar 5) | excluded: not an accelerator company (neuralink alumni founders, not yc) |
| muon space | none | $250m series c at $1.5b (aug 20) | excluded: no yc directory page exists (404); no other listed program found |
| tandem technology | not verified | $100m series b led by accel (jan) | below cutoff; accelerator status not verified |
| radar (rfid retail) | not verified | $170m series b (may) | not verified as an accelerator company; if it were, it would tie #7 - flagged for follow-up |
| midi health | none found | $100m series d (feb) | below cutoff; no accelerator link found |
| mercury (banking) | none | $200m series d (may) | excluded: not an accelerator company |
| rippling, deel, brex, gusto, faire, razorpay, scale ai, monzo, rappi, opensea | yc alumni | no 2026 primary round found (rippling's and deel's last rounds were 2025; brex was acquired by capital one in jan 2026) | no 2026 round |
| datarobot, talkdesk (techstars / 500 alumni), airalo (antler), cleo (ef) | various | no 2026 round found | no 2026 round |
| 2026 batch companies from the accelerators-2026.md file (yc w26/s26, techstars spring 2026, speedrun sr006/sr007, antler us spring 2026, sanabil batch 11) | current cohorts | only seed-scale rounds found (e.g. speedrun's cascade $3.5m, space $2.4m, blueprint c$1.4m; yc's conntour $7m, pocket $11m) | none within two orders of magnitude of the cutoff; the largest 2026 rounds all come from alumni of 2015-2025 batches |
counts: 45 candidates checked; 10 ranked with two independent sources each; 2 items inside the ranked entries flagged single-source (astranis' $2.8b valuation, hightouch's $100m arr); 2 large rounds not rankable because the size is undisclosed (afterquery, flutterwave); 1 reported-only round excluded (flock safety); 2 excluded on program-participation grounds (baseten, lovable).
methods note
- started from /home/claude/ops/research/accelerators-2026.md (about 250 named 2026-cohort companies). those companies are months old and none had raised anything near $100m, so the search widened to all alumni of the ten programs.
- discovery queries (websearch): "largest funding rounds 2026 y combinator alumni", "yc-backed raises 2026 billion valuation", "techcrunch 2026 y combinator raises series b", company-specific queries ("kalshi raises 2026", "replit raises 2026", "whatnot raises 2026", "supabase raises 2026", "zepto 2026", "flutterwave 2026", etc.), and program-specific queries ("techstars alum raises 2026", "a16z speedrun alum raises 2026", "antler portfolio raises 2026", "entrepreneur first alumni raises 2026", "sequoia arc alum raises 2026", "pearx alum raises 2026").
- the most useful sources were: techcrunch's mid-year unicorn roundup (jul 5, 2026) and its y-combinator tag page; alleywatch's monthly "largest us funding rounds" lists for february through july 2026 (scanned line by line for alumni names - this surfaced astranis, exa, flock safety, hightouch, avoca, and slash); company press releases on businesswire/prnewswire; and the yc company directory (ycombinator.com/companies/) to confirm batches - a 404 there (muon space) was treated as "not yc".
- accelerator status was confirmed only via the program's own directory or the program's own profile of the company. investor-only relationships (spc in baseten, antler in lovable, 500 global in deep infra) were not counted as "went through".
- every round in the top 10 was fetched from at least one announcement source and one independent outlet. numbers in dispute (eight sleep $50m vs $150m; astranis $300m vs $450m/$455m) were resolved in favour of the company's own statement or the majority of outlets and the discrepancy is noted.
- the websearch budget for this session ran out after the final replit revenue query, so a handful of secondary checks (tandem's and radar's accelerator status, slash's batch) were not completed; they are flagged rather than filled in.
- dates are announcement dates in us time; "today" is september 4, 2026. yc's summer 2026 demo day (sep 10) and later events fall outside the window.