This column originally appeared on Real Money Pro at 8:18 a.m. EDT on June 13.NEW YORK ( Real Money) -- Over the past four weeks, I have suggested that the complexion and character of the market is changing. My baseline expectation is that the U.S. stock market is morphing from a one-way market toward a two-way market. Over the past 12 trading days, there have been eight triple-digit moves. In the past 31 trading days, there have been 11 triple-digit daily changes (five up and six down). A market without memory from day to day could continue for some time. If I am correct in my assessment, there is a need for a new market playbook in order to deal with the renewed volatility and lack of a primary trend. We have to adapt to a potentially changing market backdrop. The debate as to whether global economic growth is slowing and whether optimistic profit expectations will be met will remain the core narrative -- certainly, at least, over the summer months. Though a data-dependency will likely lead to volatility, as markets react to the releases, to me, the accumulating body of evidence is that disappointment lies ahead. My view continues to be that the global economies face a false economic dawn, the profit landscape is challenging and stocks are overpriced. (Note: Overnight, the World Bank lowered its global economic forecast for 2013.) As I have counseled recently, trading sardines (opportunistically) will probably be a more profitable way to deliver good investment returns than eating (investing) sardines (which has led to prosperity over the past few years). At the very least, more active trading might be considered as an adjunct to longer-term investing. Of course, a more tactical trading-oriented approach (over investing) is not for everyone, but we can profit by trading opportunistically. But changing our modus operandi is easier said/written than done. Start slowly, and ease into increased trading activity. Expand your involvement only when you are comfortable with a more action-oriented strategy and until you grow more comfortable with what I suspect will be heightened volatility in a market without memory from day to day.