As I write this morning, the market is selling off broadly, raising the question of whether this downtrend will gain real momentum. The truth is no one knows. What we do know is that the Dow is just seven trading days off its all-time high, while the Nasdaq, where growth stocks have been hit harder, has been losing momentum since mid-February. Thus, technically, these indices have been diverging for three months and now the odds are growing that the broad market will follow the Nasdaq’s lead on the downside.