Friday 18 September 2026
Top stories today:
Anthropic’s Claude used to hack OpenAI, access private code repo
OpenAI launches Astra for Law with legal search, analysis capabilities
New U.S. tariffs delayed until after Trump-Xi summit on Sep. 24
SEC unveils 5-year exemption for tokenized stock trading
Meta’s Muse launches on Mac with file, app access
0. Data & Calendar
All values as of 6 AM ET / 3 AM PT, other than S&P500 and NASDAQ close (4 PM ET / 1 PM PT).
No major events today.
Listen to our AI-generated podcast summarizing today’s newsletter (beware of hallucinations):
1. Anthropic’s Claude used to hack OpenAI, access private code repository
Claude Opus 4.8 and Opus 5 were used, Hacktron AI, the security firm behind the research, said.
Opus 5 successfully produced the reliable exploit, the researchers said.
<72 hours from initial discovery to accessing OpenAI’s repo.
OpenAI paid the researchers a $6,500 bounty and said it fixed the security flaws.
Separately, Anthropic said Claude leads 26% of its AI R&D work and collaborates on 90%+.
Anthropic has redesigned Claude projects to manage work across parallel threads, starting in Claude Code.
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3. OpenAI launches Astra for Law, combining GPT-6 Astra with legal search, analysis capabilities
Astra for Law has surpassed GPT-6 Astra on the Vals AI Legal Research Bench validation set:
Initially available to select law firms through OpenAI’s Trusted Access in ChatGPT and Codex, with API access coming soon.
Latham & Watkins is working with OpenAI to design information permissions, ethical walls, client instructions, and oversight.
Also, OpenAI and Cooley co-launched GO Public to quickly draft and revise S-1 filings.
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5. New U.S. tariffs said to be delayed until after Trump-Xi summit on Sep. 24
A 7.5% tariff on Chinese goods was earlier set to be recommended in a trade report ahead of the summit.
China previously signaled retaliation if U.S. tariffs exceed levels prevailing when the trade truce was struck.
The delay would also apply to other U.S. trading partners alongside China.
Trump also announced a state dinner for Xi, with Tim Cook and Sam Altman poised to attend.
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7. SEC unveils 5-year exemption for tokenized stock trading
A 5-year exemption from dealer registration requirements for liquidity providers in tokenized stocks has also been offered.
Securitize and Bullish stocks closed +15% and +9%, respectively, after the order.
Separately, the CFTC allowed crypto wallets to enable derivatives trading without registering as introducing brokers.
