Leveraged single-stock ETFs on Micron and SanDisk can't be held for long because decay keeps them from matching the underlying stocks' highs. When Micron and SanDisk next reach all-time highs, those ETFs won't, and the longer that takes, the further below they will be. Holders who tried to ride the wave with them are getting smoked; they shouldn't be held for more than a few days. x.comÂ