Tuesday briefing: How an unknown Chinese startup wiped $593bn from the value of an AI giant

In today's newsletter: the US had a huge head start on artificial intelligence - but now a low-cost rival from Hangzhou has turned the industry on its head

Good morning. Since the emergence of ChatGPT, OpenAI's groundbreaking artificial intelligence tool, American companies have appeared to have a huge head start in the development of the most significant technology of its generation.

But now a small Chinese rival has emerged that appears to match what OpenAI and the other US giants can do at a much lower cost, and without the same hunger for computing power that has made the chip manufacturer Nvidia the most valuable company in the world. The result was a stunning collapse in the value of Big Tech stocks yesterday - and a $593bn fall in the value of Nvidia, the biggest in the US stock market's history.

Gaza ceasefire | Tens of thousands of Palestinians flooded back into northern Gaza on Monday after Israel opened military checkpoints that had divided the strip for more than a year, ending a forced exile from homes and loved ones that many feared could become permanent.

UK security | Hindu nationalism, misogyny and the manosphere" have been identified as breeding grounds for extremism in a leaked government report commissioned after last summer's riots. The rapid analytical sprint" also dismissed claims of two-tier policing" as a rightwing extremist narrative".

Auschwitz | Elderly former inmates of Auschwitz gathered for perhaps the final time on the 80th anniversary of the concentration camp's liberation. In remarks at the event, four survivors warned world leaders against the danger of rising antisemitism.

Roman Abramovich | An offshore scheme appears to have helped companies owned by the billionaire Roman Abramovich avoid duties potentially amounting to tens of millions of dollars. Abramovich's lawyers denied he had knowledge of or was personally responsible for any alleged tax evasion.

Local government | Bristol city council could become the first local authority in England to collect black rubbish bins only once every four weeks. The Green-led council says switching from a two- to four-weekly collection would save it more than 2m a year and help reverse a dip in recycling rates.