Morning Bid: Chip dip U.S. chip stocks rallied Monday but Asian shares fell Tuesday as concerns about the sustainability of AI-driven demand weighed on Samsung and SK Hynix, dragging South Korea's KOSPI down 5%. Samsung's 19-fold profit jump failed to lift its stock, which fell 7%, while Microsoft cut 4,800 gaming jobs and oil rose on Iran missile reports. By Anna Szymanski July 7 Reuters - What matters in U.S. and global markets today By Anna Szymanski, Editor-in-Charge, Reuters Open Interest U.S. chip stocks staged a comeback on Monday, but that momentum stalled heading into Tuesday as concerns about the durability of the AI chip frenzy weighed on shares in Asia trading. Memory chipmaker Samsung Electronics' shares fell nearly 7% on Tuesday even though it revealed a 19-fold jump in second-quarter operating profit, while rival SK Hynix also slid, dragging down South Korea's chip-heavy KOSPI index around 5%. I'll get into that and more below. But first, listen to the latest episode of the Morning Bid daily podcast, where we dig into the market reaction to Samsung's eye-popping results. Subscribe to hear Reuters journalists discuss the biggest news in markets and finance seven days a week. CHIP DIP Monday's chip rally stateside appeared to be triggered by news that Broadcom would extend a deal with Apple to provide the iPhone maker with custom chips through 2031. The S&P 500 and Nasdaq closed higher amid the rally. Nasdaq futures were down more than 1% before the bell on Tuesday, however, following the ructions in Asia trading. The pullback in Asian tech stocks on Tuesday could indicate that much of the upside from soaring chip demand is already priced in, while jitters about the sustainability of the bonanza continue to rise. It's worth remembering that Samsung's share price has already more than doubled year-to-date, while SK Hynix's has more than tripled. Elsewhere in tech, Microsoft saw its shares fall nearly 1% on Monday after it announced that it was cutting around 4,800 jobs as it seeks to restructure its gaming division. This follows a roughly 20% drop in the company's share price in the first six months of 2026. Over in FX, the yen strengthened slightly on Tuesday but remained near 40-year lows around 162 per dollar as traders stayed watchful for potential intervention from Japan's authorities. Meanwhile, oil prices climbed following reports that Iran fired missiles at commercial ships in the Strait of Hormuz yesterday, with Brent crude trading at nearly $73 per barrel. Tuesday also sees the start of the NATO summit in Ankara, Turkey, where European defence spending is likely to be top of the agenda as leaders seek to demonstrate how they plan to hit increased NATO spending targets pushed for by President Donald Trump. Another point of interest will be President Trump's meeting with Ukrainian President Volodymyr Zelenskiy on the sidelines of the summit, slated for Wednesday. Trump on Monday repeated familiar claims that an end to the Ukraine war could be close.