Nasdaq and S&P 500 slip while Dow hits record high

STORY: Wall Street's main indexes ended mixed on Tuesday, with the Dow gaining just under two-thirds of a percent to notch its second straight record-high close... while the S&P 500 shed more than half a percent and the Nasdaq dropped more than one percent.Shares of Elon Musk's SpaceX ended nearly 5% higher, paring earlier gains. For much of the session, the rocket and AI company's value was above that of Amazon, and it briefly surpassed Microsoft's valuation, as retail investors continued to pour into the stock after its record-breaking IPO.But Amol Dhargalkar, chairman and managing partner at Chatham Financial, warned of several risks that could trigger volatility for SpaceX and other AI-related stocks."I think that's a really difficult position to be in as a retail investor, especially when you consider the fact that there is a lot of risk, not just in the business model, but these are names where the cash flows are likely far into the future. And we are not in a period of 0% or negative interest rates or even declining interest rates at this point. There's a lot of question as to whether interest rates will continue to be flat or will they go up. And that can certainly be a meaningful drag on valuations of high growth companies, especially where that growth is out far into the future."Investors will look for clues on where interest rates are headed when the Federal Reserve concludes its latest two-day policy meeting on Wednesday, with Kevin Warsh holding his first press conference as Fed chair.Other stocks on the move included shares of Olin, which sank nearly 6% after the chemical producer said it would acquire Huntsman in an all-stock deal valued at more than $2.4 billion. Huntsman shares also fell as the offer stood at a discount to the stock's recent price.:: Yum BrandsAnd shares of Yum Brands rose after the fast-food company said it would sell its Pizza Hut chain for $2.7 billion, against a backdrop of softer consumer spending across the fast-food industry.