Y Combinator engagement report
@ycombinator - 1.6M followers on X
Measured over 79 original posts from a 30-day window, last computed on September 1, 2026.
Engagement
A typical post picks up 205 interactions against 1.6M followers, an engagement rate of 0.013%. Measured over 79 original posts, its engagement rate beats 49% of 3,774 tracked accounts of a similar size, which puts it in the middle of its size range rather than at either end. Posts are seen about 40K times each, and 0.519% of those impressions turn into an interaction. That is about 2.40% of the follower count, which is the gap between an audience on paper and an audience in a timeline. Posting runs at about 11.3 posts a day over the last 30 days, with activity on roughly 63% of days. Most posts go out around 17:00 UTC, and Tuesday is the busiest day of the week. Of the 79 posts sampled, 91% carry an image or video, 6% are part of a thread and 29% link out. The account's strongest tracked post pulled 15K interactions, about 74x its own typical post.
Measured over 79 original posts from a 30-day window, last computed on September 1, 2026.
Compared with accounts its own size
Y Combinator's engagement rate beats 49% of the tracked X accounts closest to it in follower count (3,774 accounts, accounts of similar size (decile 10 of 10)). A percentile is spread evenly by construction, so 50 really is the middle of that group and 90 really is its top tenth.
On engagement per impression rather than per follower it beats 39% of the same group. When those two numbers disagree, the gap is about how far its posts travel rather than how people react to them.
Where this sits in the catalog
At 0.013%, Y Combinator sits above the 25th percentile of the 36,654 accounts in this comparison. That places it in the below the median band, which runs 0.012% to 0.08%.
Show the percentile table
| Percentile | Engagement rate |
|---|---|
| 10th percentile | 0.002% |
| 25th percentile | 0.012% |
| 50th percentile | 0.08% |
| 75th percentile | 0.433% |
| 90th percentile | 2.10% |
| 99th percentile | 160.5% |
This ruler is the whole measured catalog, not a size-matched group: it shows where the raw rate falls across every account we can measure, all of which are large. For a like-for-like comparison, read the size-band percentile above instead. See how the bands are built
Posting timing
This account posts most often around 17:00 UTC, and Tuesday is its busiest day of the week. The bars below are the catalog-wide pattern, with this account's own busiest slot marked. They do not show how this account performs at each hour: we keep one aggregate per account, not one per hour, so that measurement does not exist in our data.
Show engagement by hour posted, utc as a table
| Hour (UTC) | Vs author median | Posts |
|---|---|---|
| 00:00 UTC | -1% | 51K |
| 01:00 UTC | -2% | 52K |
| 02:00 UTC | -3% | 50K |
| 03:00 UTC | -4% | 53K |
| 04:00 UTC | -6% | 43K |
| 05:00 UTC | -4% | 42K |
| 06:00 UTC | -4% | 48K |
| 07:00 UTC | -5% | 52K |
| 08:00 UTC | -4% | 61K |
| 09:00 UTC | -3% | 70K |
| 10:00 UTC | -2% | 72K |
| 11:00 UTC | -3% | 78K |
| 12:00 UTC | -2% | 86K |
| 13:00 UTC | -2% | 94K |
| 14:00 UTC | -4% | 97K |
| 15:00 UTC | -2% | 101K |
| 16:00 UTC | -3% | 98K |
| 17:00 UTC | -2% | 91K |
| 18:00 UTC | -1% | 85K |
| 19:00 UTC | -1% | 80K |
| 20:00 UTC | -1% | 74K |
| 21:00 UTC | -1% | 66K |
| 22:00 UTC | -1% | 57K |
| 23:00 UTC | -2% | 52K |
Show engagement by day of week as a table
| Day | Vs author median | Posts |
|---|---|---|
| Sunday | +4% | 231K |
| Monday | 0% | 288K |
| Tuesday | -2% | 278K |
| Wednesday | -1% | 251K |
| Thursday | -1% | 245K |
| Friday | -3% | 253K |
| Saturday | +3% | 227K |
Best tweets
- Aug 18, 202674x their median
Many drugs work by binding to a specific target in the body and blocking or changing what it does. An important first step in the drug development process is designing a molecule that can bind tightly to its target. Traditionally, that's meant weeks or months of expert work per target, sifting through a large number of candidates to identify the few that work. We wanted to test if Claude could successfully design novel protein binders from scratch (also called de novo design). With a protein design prompt written by a human expert, Claude autonomously designed protein binders against 14 out of 15 targets. We then worked with Adaptyv Bio and Twist Bioscience, who independently built and tested the proteins Claude designed.
- Aug 19, 202620x their median
The trouble with having Zane Hengsperger visit your house is that instead of the usual random house gift, he brings you a 10 pound block of solid aluminum. https://t.co/OYS0uZdwgG
- Jul 1, 202612x their median
Two reports from @SamLyman33 and @bitcoinpolicy document a coordinated foreign influence campaign against American AI — running through CCP state media, a Shanghai-based Marxist's nonprofit network, and foreign billionaire dark money that has funneled $2B+ into US advocacy infrastructure. AI doomerism isn't as organic as it looks.
- Aug 19, 202612x their median
Introducing our tech roadmap at @cosmic_robotics to start autonomous city construction on Mars in the mid-2030s. Our team includes senior talent from SpaceX, Tesla, Google, Amazon, Zoox, Nuro, and Autodesk. We're already deploying robots on large-scale construction sites. Link to roadmap in the thread below:
- Aug 23, 202612x their median
My conversation with Sam Altman (@sama), co-founder & CEO of @OpenAI. 0:00 Tobi Lütke, AI-Native Companies & Why Adoption Moves Slowly 5:45 Sam's Own Resistance to AI & the Missing iPhone Moment 10:00 Models, Compute, Power Laws & Non-Consensus Talent 18:37 From AI-Obsessed Kid to Founder, Investor & Back Again 23:19 Impossible Problems, Scientific Discovery & Human Connection 30:16 AI's Two Biggest Risks: Loss of Control & Centralized Power 33:09 Iterative Deployment, AI Safety & Learning From Reality 40:27 Why People Fear AI & the Coming Small-Business Boom 46:13 Context, Memory & the Next Way We Will Work With AI 49:17 OpenAI's Platform Strategy & Killing Good Ideas 53:20 Peter Thiel, Paul Graham & the Value of Nonlinear Thinkers 1:00:42 How Y Combinator Changed Startups & Shaped OpenAI 1:04:03 Learning More From Success & the Power of Repetition 1:09:45 Building OpenAI Without Customers, a Product or a Playbook 1:15:57 Letters to His Son & Preserving the Story Includes paid partnerships.
- Aug 19, 20269.5x their median
Meeting the demand for compute is becoming impossible. At Atomarine we are building the next generation of AI infrastructure: the most scalable, cheapest and most climate friendly form of standalone compute on Earth. https://t.co/OoecqwIQeQ
- Aug 30, 20268.6x their median
"The way to get the very best startup ideas is not to look for startup ideas. If you’re consciously looking for them, you’ll be too conservative. You’ll lop off the outliers." Instead, work on projects with your friends. Build things you think would be cool. Paul Graham on How to Earn a Billion Dollars: https://t.co/Xa3fTRxPII
- Aug 19, 20268.1x their median
Today, we raised a $13M series A to solve the GPU shortage Trillions are being spent on GPU CapEx while 80% of it sits idle The capacity already exists Virtualizing GPUs unlocks it Backed by Matrix, YC, and CEAS https://t.co/88zFVc96LC
- Aug 19, 20267.3x their median
In 2013, @cjoneslevy created the SAFE at YC. It's since been used by YC founders to raise $15B+ and has become the standard way startups raise money. So we're launching Send a SAFE: a free tool to generate, sign, & send one in ~2 minutes, built to be used by founders (and their AI agents).
- Aug 18, 20266.9x their median
Signups are now open on Code[dot]Storage. Today, more new repos are created per second on Code Storage than any other platform. Lovable, Bolt, Amp, Poke, and many more of the largest agentic workloads store their code and agent memory at scale using https://t.co/oJLq0faUTg. https://t.co/glGIYEnFzO
Ranked by total interactions across everything we have tracked for this account, which is a longer history than the 30-day window the rates above use. The multiple compares each post to this account's own median.
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Reading these numbers
A typical post picks up 205 interactions against 1.6M followers, an engagement rate of 0.013%. Measured over 79 original posts, its engagement rate beats 49% of 3,774 tracked accounts of a similar size, which puts it in the middle of its size range rather than at either end. Posts are seen about 40K times each, and 0.519% of those impressions turn into an interaction. That is about 2.40% of the follower count, which is the gap between an audience on paper and an audience in a timeline. Posting runs at about 11.3 posts a day over the last 30 days, with activity on roughly 63% of days. Most posts go out around 17:00 UTC, and Tuesday is the busiest day of the week. Of the 79 posts sampled, 91% carry an image or video, 6% are part of a thread and 29% link out. The account's strongest tracked post pulled 15K interactions, about 74x its own typical post.
- What is Y Combinator's engagement rate on X?
- Y Combinator (@ycombinator) has an engagement rate of 0.013%, based on the median interactions across 79 original posts from the last 30 days against 1,645,691 followers. Replies, reposts and quote-posts of other people are excluded from that sample.
- Is that a good engagement rate?
- At 0.013%, Y Combinator sits above the 25th percentile of the 36,654 accounts in this comparison. Those comparison accounts are all large ones, because our scanning cadence is weighted towards big accounts, so this is a ranking among peers of similar scale rather than a ranking across X.
- Does @ycombinator have real engagement?
- Its engagement rate beats 49% of the tracked X accounts closest to it in follower count (3,774 accounts), which puts it in the middle of its size range group. Ranking inside a size band matters because engagement rate falls as accounts grow, so a raw rate would mostly re-measure the follower count. It is a starting point for a look at follower quality, not a verdict on it.
- When does @ycombinator post?
- Most posts go out around 17:00 UTC, and Tuesday is its busiest day, at roughly 11.3 posts per day across the measured window.