Stocks are at a real crossroads this week, as a trifecta of events conspire to make this potentially the most pivotal period of the year. The outcome could determine the market's direction for the next several months. If stocks end this week lower, conservative growth investors may wish to sit out the next couple of months in cash, as an increase in downward volatility could sap their willingness to wait out the severe downdrafts that may lie ahead. More aggressive private investors may want to create portfolios that could provide buoyancy, and perhaps even an absolute lift, in difficult seas. The problem is that this year is shaping up to resemble 1997-99 or 2000-02 much more than 2003. In those earlier periods, there were distinct groups of stocks that went up most of the time and distinct groups of stocks that went down most of the time. In contrast, in 2003 there was a broader rise in the market that lulled many investors into complacency.