US tech stocks are sinking, with Nasdaq-100 futures down 0.9% and S&P 500 futures dropping 0.2%, as a sell-off in memory chipmakers deepens. South Korea's Kospi benchmark tumbled over 10% on Tuesday, with shares of SK Hynix and Samsung Electronics falling more than 14% and 13% respectively. This sentiment is driven by concerns over AI circular financing deals, such as Nvidia exploring a $250 billion funding backstop for OpenAI, and increasing Chinese competition in AI. Meanwhile, oil prices retreated as the US and Iran halted active fighting and began diplomatic talks, while the Federal Reserve commenced a two-day policy meeting, with market participants divided on the likelihood of a rate hike.