To The Moon

If you own Sandisk, Western Digital, or Micron Technology stock, congrats.They -- and any number of other red-hot AI momentum plays -- have more than doubled in the past year. Now, for a dose of reality: Companies that enjoy a huge pop end up limping along for years.That's the conclusion of an analysis of the past 40-some years by Renaissance Macro Research, or RenMac. The firm's Rafael Sanhueza, a technical researcher, and Jeffrey deGraaf, chairman and head of technical research, looked at what happens after a stock doubles in price over a short period -- anywhere from 10 to 252 trading days. They studied "bubble events" for companies in the Russell 3000 index, from 1984 to this year."Across large-cap, small-cap, and broad-market universes, stocks that double rapidly tend to underperform over the subsequent 36 months," they wrote.Sanhueza and deGraaf also warned there are dangers in betting against momentum stocks. Stocks that have doubled can keep climbing.This content was created by