CNBC Daily Open: Markets are wide awake as September ends

US President Donald Trump, from center left, US House Speaker Mike Johnson, a Republican from Louisiana, and Jensen Huang, chief executive officer of Nvidia Corp., speak to members of the media following a meeting with tech executives on artificial intelligence at the White House in Washington, DC, US, on Tuesday, Sept. 29, 2026.Tierney L. Cross | The Washington Post | Bloomberg | Getty ImagesHello, this is Hui Jie writing to you from Singapore. Welcome to another edition of CNBC's Daily Open.Rock band Green Day once asked to be woken up when September ends, but with the developments in the AI world and markets keeping a close eye on Treasury yields, investors probably won't need much help keeping awake this year.What you need to know todayWhen a document is signed in government circles, a question that usually comes up is whether it is legally binding or not. Now, U.S. President Donald Trump has introduced an ambiguous middle ground: "morally binding."Trump said Tuesday that he signed such a document with tech leaders following a luncheon at the White House, as calls to slow down the development of frontier models continue in the U.S.Some of these leaders include Nvidia chief Jens...