Venture Math · Fall 2026

SAFEs & the Accelerator

Session 02 · Accelerators & SAFEs · Christina Gilbert (Y Combinator)
Data: Carta · PitchBook · Y Combinator · re-visualized for classroom use
The accelerator that set the template: Y CombinatorDATA: PITCHBOOK · YC · CARTA

The YC standard deal, 2005 → today

What Y Combinator pays for ~7% of your company — and when they changed the instrument. The check grew 20×; the tool they invented (the SAFE) became the market standard you see overleaf.

2005 $6K / founder (<$18K) · for ~7% 2013 YC invents the SAFE (pre-money) 2018 $150K for 7% post-money SAFE 2008 $11K +$3K / founder for ~7% 2014 $120K for 7% 2022+ $125K for 7% + $375K uncapped MFN

Y Combinator standard deal, 2005–present · via CoffeeSpace timeline, Nov 2024

YC by the numbers

Twenty years of the world's largest accelerator, in five figures.

4,977
companies funded since 2005
8 → 729
first batch (S05) → largest (S21+W21)
$89B
Airbnb (W09) — highest-valued alum
$1B
Cruise (W14) — largest exit, to GM

First IPO Dropbox (S07) · first exit TextPayMe → Amazon · Reddit (S05) now ~$21B public · the SAFE was invented here in 2013.

Y Combinator · ycdb.co · market caps as of Nov 2024

The SAFE pushed complexity into Series A

Prevalence of extra preferred classes in Series A charters, 2004 → 2022 — a downstream cost of stacking pre-priced rounds.

Series SeedShadow ABoth
0255070% pre-money SAFE post-money SAFE 66% 59% 29% 200420132022

R. Bartlett via C. Harvey · Delaware A&R charters · 2004–2022

No accelerator comes close on exit value

Peak single-cohort cumulative exit value, by program (through Dec 2022). YC's best class alone has returned more than every rival's best class combined.

$0$25B$50B$75B$100B Y CombinatorMassChallengeTechstars500 Global $93.3B $17B $10.5B $1.2B · SOSV $0.6B 2012 class

PitchBook · “Quantifying the Success of YC & the Largest Accelerators,” 2023 · YC by class: 2012 $93B · 2013 $30B · 2014 $20B · 2015 $11B

The SAFE has taken over pre-seed fundraisingTEAL = SAFE · CLAY = CONVERTIBLE NOTE

SAFEs have all but replaced convertible notes

Share of pre-priced capital raised on SAFEs vs. convertible notes, by industry. Even the most note-heavy corner of the market is now a coin flip.

INDUSTRY # CHECKS EducationAdvertising techFintechWeb3SaaSConsumerHardware / ITHealthtechPharma / biotechEnergyMedical devices 98%95%92%92%83%78%71%69%66%61%48% 17%22%29%31%34%39%52% 5724903,24066811,1724,4601,8013,4342,3598301,216

Carta · 30,242 SAFEs & notes signed before any priced round · Jan 2023–May 2024

Post-money is now the default SAFE

Share of SAFEs signed post-money, 2018 → 2025. YC made it the default in 2018, then dropped the capped-and-discounted version in 2021.

050100% 14% 82% YC drops the capped- and-discounted SAFE · 2021 201820222025

Carta · 119,232 SAFEs signed before any priced equity

The more you raise on a SAFE, the more you sell

Median % of the company sold, by SAFE round size. Founders who stack multiple SAFEs feel it compound.

0%81725% 3.0 7.1 11.2 16.4 21.4 <$250K$250–499K$500–999K$1–2.4M$2.5–4.9M

Carta · 1,503 US companies on post-money SAFEs · H1 2024

Pre-seed keeps shrinking — under $500K is now half the market

Share of US pre-priced rounds (SAFEs & notes) raising under $500K, by quarter. The sub-$250K band is doing the shrinking.

Under $250K$250K–$499K
02550% 38 40 42 39 40 41 42 41 43 44 47 49% 202320242025

Carta · US pre-priced rounds (SAFEs & convertible notes) · Q1 2023–Q4 2025