On Sept. 30, Micron Technology ( MU +4.22% ) reported a monster fiscal fourth-quarter earnings report. The company set records across revenue, profitability, and cash generation. Ordinarily, blowout earnings results give investors plenty of reasons to celebrate.

However, Micron stock has been moving in the opposite direction over the last month. As of market close on Oct. 22, shares declined roughly 20% since Micron reported earnings and were trading nearly 29% below their all-time high.

What's important to understand is that Micron's sell-off isn't a reflection of a deteriorating business. Rather, investors are concerned about the sustainability of artificial intelligence (AI) spending, elevated valuations , and the likelihood that the memory industry's unusually high profitability won't last forever.…