Wall Street indexes closed higher on Wednesday, led by the tech-heavy Nasdaq as Nvidia briefly reached a $4 trillion valuation, and Federal Reserve meeting minutes fueled hopes that inflation pressures from President Donald Trump's tariffs would not derail interest rate cuts this year.

Probably the biggest concern about the stock, though, is that its valuation is unjustifiable. Palantir's shares trade at 238 times forward earnings. Its price/earnings-to-growth (PEG) ratio, which factors in analysts' earnings growth projections over the next five years, is a sky-high 4.18, according to LSEG.

Wall Street was set for a slightly higher open on Tuesday as a full U.S. approval of a COVID-19 shot boosted shares of energy and travel-related companies, while gains in technology stocks put the ...