GPT-5.5 becomes the default Nasdaq hits all-time high

On May 5, OpenAI announced that it has made GPT-5.5 Instant the default model for ChatGPT, reducing hallucination rates by 52.5% compared to the previous GPT-5.3 Instant in high-risk domains such as healthcare, legal, and finance, and decreasing inaccurate responses to user-reported factual errors by 37.3%. The model will also be released simultaneously on the API, with reduced emoji abuse.

On May 5, the S&P500 closed up 0.81% at 7,259.22, the Nasdaq at 25,326.13, and the Dow up 356 points to 49,298.34. The technology sector led the index gain with a rise exceeding 2%, while Russell 2000 and Nasdaq both set intraday record highs. Declining oil prices and expectations for peace negotiations with Iran were key catalysts.

On May 5, Coinbase announced a reduction of approximately 700 employees (14%) and flattened the management layer into "player-coach" roles, declaring the implementation of "AI native pods" where AI agents and single-person teams absorb the responsibilities of engineers, designers, and product managers. The company projected one-time costs of $50-60 million and annual savings of $120-150 million.

The United States suspended its Strait of Hormuz escort operation 'Project Freedom' on May 5. President Trump cited progress toward a "comprehensive final agreement" with Iran as the reason, while simultaneously warning of the possibility of "far more intense bombardment" if a peace agreement is not reached. The draft agreement takes the form of a ceasefire memorandum that would trigger a 30-day negotiation period.

In the West Bengal state assembly elections counted on May 4, the BJP emerged as the majority party, establishing the first right-wing government since 1937. Chief Minister Mamata Banerjee lost in her home constituency of Bhabanipur to BJP's Suvendu Adhikari and refused to resign, alleging "rigged elections." The voter turnout reached a record 92.93%.

Bret Taylor's AI customer service startup Sierra raised $950 million led by Tiger Global and GV at a $15.8 billion valuation. The company reached $150 million ARR within eight quarters and achieved over 40% penetration among Fortune 50 companies. The competition in enterprise AI agent market is accelerating.

Pfizer reported on May 5 that Q1 revenue of $14.45 billion (+5% year-over-year) and EPS of $0.75 exceeded consensus of $0.72. While COVID vaccine revenue declined 59% to $232 million and Paxlovid was down 62%, existing blockbusters like Eliquis and new or acquired assets offset these declines. The company reconfirmed 2026 revenue guidance of $59.5-62.5 billion.