Elon Musk had a busy night on X on Oct. 18. He mocked Yann LeCun's math on a flying car. Hours later, he mocked Anthropic's newest pledge.
Musk runs Tesla, SpaceX and xAI. LeCun left Meta last year to start Advanced Machine Intelligence Labs6. Anthropic had just promised away a slice of itself worth billions, and a scientist had just done the math Musk skipped. All three names landed in Musk's replies before midnight, and the two fights read very differently once a reader checks each one's numbers.
Two Jabs in Under Ten Hours
At 2:41 p.m. UTC, Musk replied to LeCun. "I fart in your general direction," he wrote7. LeCun had spent the day before doing math on Tesla's new Roadster.
The car flew at a SpaceX test site near McGregor, Texas, on Oct. 154. Thrusters built with SpaceX pushed it off a ramp, burning compressed air rather than rocket fuel. Tesla says the thrusters add four to five times the force tires alone can put down.
It hit 60 mph in under a second during the demo4. LeCun ran the numbers anyway.
"Okay, so it's just compressed air. Easier. But crappy specific impulse (less than 50 seconds). Even assuming that 50% of the mass of the car is the compressed air, that gives you less than 10s of useful thrust (with thrust-to-weight ratio larger than 1.0)," LeCun wrote on Oct. 178. Specific impulse measures how much push a thruster gets from each pound of propellant it burns5. A higher number means a more efficient engine.
Musk skipped the math and answered with a joke. LeCun replied with a joke of his own. "From a high-pressure belly, your fart might propel you upward and forward," he wrote. "Come to think of it, that's exactly how your car is powered: A 700 bar, 600 liter, 3 second, noisy fart"8.
Three hours later, Musk mocked Anthropic too.
Anthropic's Twentieth, Spelled Out
Anthropic posted its own news at 6:07 p.m. UTC. "We're committing a portion of Anthropic's shares to the Anthropic Public Benefit Fund, a new wholly owned entity dedicated entirely to the public benefit," the company wrote9.
The fund starts with 5% of Anthropic's shares, pending a vote from stockholders1. Anthropic's last funding round valued the company at $965 billion3. Five percent of that comes to roughly $48 billion.
Its board can add 2 more percentage points for every 50% jump in the company's value. That jump starts above a baseline Anthropic has yet to publish1.
Anthropic Gives Its New Fund 5 Percent of the Company
Share of Anthropic's own equity committed to the Public Benefit Fund today, against its $965 billion valuation
Sources: Anthropic [1]; TechCrunch [3]. Chart by Ryan Elliott Dennis.
The numbers behind this chart
| Item | Value |
|---|---|
| Pledged to the fund today | 5% |
| Still held elsewhere at Anthropic | 95% |
| Whole | 100% |
Anthropic's co-founders already pledged 80% of their own shares at the company's founding1. About half of its employees give away equity too, matched by the company. Add the three pledges up, and roughly 20% of Anthropic will eventually serve the public.
Anthropic is also preparing for a public listing3. A visible pledge of this size reads well on a prospectus that investors will study line by line.
The fund takes the shape of an LLC, rather than a nonprofit1. That choice buys flexibility in how the money moves. A 501(c)(3) answers to a regulator's charitable-purpose test. The LLC answers mainly to Anthropic's own board.
A Co-Founder Defends It, a Czar Doubts It
Jack Clark, Anthropic's co-founder and head of public benefit, posted the news himself. "Between this and our prior commitments, roughly 20% of all Anthropic equity will be dedicated to the public good, and that commitment can grow as Anthropic grows," he wrote10.
David Sacks read the same number differently. He serves as the White House's AI and crypto czar, and he replied straight to Clark's post. "You've put 20% of your equity in an LLC. Whether it serves the public good remains to be seen," Sacks wrote11.
Musk posted his own reply two hours after Anthropic's announcement. "I recommend giving the shares directly to the public," he wrote7. After midnight, he added one line more: "This is what I will be doing".
xAI, Musk's own AI company, competes with Anthropic for enterprise business. His suggestion costs him zero and asks a competitor for a harder version of a gift Anthropic already promised.
Clark, Anthropic and Musk each skipped the same detail: a named recipient. TechCrunch reported that Anthropic left the fund's governance and its first payouts for a later announcement2.
Musk's Jab at LeCun Draws Nearly 2 Times Anthropic's Own Likes
Likes on five posts from four X accounts, Oct. 18 to 19, 2026
Each bar is one post on X; its length is how many likes it had drawn when checked on Oct. 19, 2026.
Likes were checked in one pass on Oct. 19, 2026 and keep climbing on every post.
Sources: Elon Musk on X [7]; Yann LeCun on X [8]; Anthropic on X [9]; David Sacks on X [11]. Chart by Ryan Elliott Dennis.
The numbers behind this chart
| Item | Value |
|---|---|
| Musk jabs LeCun | 29,466 likes |
| Musk replies to Anthropic | 28,979 likes |
| Anthropic announces the fund | 14,973 likes |
| Sacks doubts the fund | 3,419 likes |
| LeCun's fart-joke reply | 3,303 likes |
What to do
Read the filing behind a pledge of this kind before the reactions to it. Anthropic's own post names a percentage and a dollar figure, with the rest still to come. Watch for the public benefit report Anthropic promised, and judge the twentieth it gave away by who actually receives it.
Cite the fund's own terms instead of a headline, if your firm points to Anthropic's record in a pitch or a policy brief. The stockholder vote on the 5% has yet to happen. A valuation baseline Anthropic has kept private still decides when the extra 2% a year arrives.
By the numbers
- 5%: share of Anthropic's shares committed to the Public Benefit Fund today, pending stockholder approval1.
- $48 billion: value of that 5% stake, based on Anthropic's $965 billion valuation from its May 2026 funding round13.
- 20%: share of all Anthropic equity the fund and its prior pledges will eventually cover1.
- 29,466: the likes on Musk's jab at LeCun, the most of any post that night7.
- 28,979: Musk's reply telling Anthropic to give its shares directly to the public pulled nearly as many7.
- 14,973: Anthropic's own announcement of the fund earned this count9.
- 3,419: David Sacks' reply, doubting the fund serves the public good, drew far fewer11.
- 3,303: LeCun closed the night with a joke about his own car's "noisy fart" of thrust8.
What to watch
Anthropic has promised a public benefit report and more detail on the fund's governance. Watch for a named recipient, a payout date or a board member in the next announcement. The pledge still needs a stockholder vote before the 5% takes effect. Anthropic's valuation would also need to clear a 50% jump above its baseline before the extra 2% arrives.
Sources
- Anthropic, "Investing in the public benefit," Anthropic, Oct. 18, 2026, https://www.anthropic.com/news/public-benefit-fund
- Anthony Ha, "Anthropic says it's committing 5% of its shares to a 'public benefit fund,'" TechCrunch, Oct. 18, 2026, https://techcrunch.com/2026/10/18/anthropic-says-its-committing-5-of-its-shares-to-a-public-benefit-fund/
- Rebecca Bellan, "Anthropic raises $65 billion, nears $1T valuation ahead of IPO," TechCrunch, May 28, 2026, https://techcrunch.com/2026/05/28/anthropic-raises-65-billion-nears-1t-valuation-ahead-of-ipo/
- Landon Mion, "Tesla's new Roadster makes a flying debut, hitting 60 MPH in under a second," Fox Business, Oct. 15, 2026, https://www.foxbusiness.com/technology/teslas-new-roadster-makes-flying-debut-hitting-60-mph-under-second
- Wikipedia contributors, "Specific impulse," Wikipedia, accessed Oct. 19, 2026, https://en.wikipedia.org/wiki/Specific_impulse
- Wikipedia contributors, "Yann LeCun," Wikipedia, accessed Oct. 19, 2026, https://en.wikipedia.org/wiki/Yann_LeCun
- Elon Musk (@elonmusk), posts on X, Oct. 18-19, 2026, https://x.com/elonmusk/status/2111829939624300698
- Yann LeCun (@ylecun), posts on X, Oct. 17-18, 2026, https://x.com/ylecun/status/2111496760807895207
- Anthropic (@AnthropicAI), post on X, Oct. 18, 2026, https://x.com/AnthropicAI/status/2111881963657412903
- Jack Clark (@jackclarkSF), post on X, Oct. 18, 2026, https://x.com/jackclarkSF/status/2111918212946309445
- David Sacks (@DavidSacks), post on X, Oct. 18, 2026, https://x.com/DavidSacks/status/2111958783396385152