In summary, while we have profound concerns about how markets will evolve over the coming years – concerns we elaborate in more detail elsewhere in our Annual Outlook – our base case for 2017 attaches a relatively low likelihood to either a robust bull market or the onset of a multi-period bear market. High valuations will continue to rein in upside growth, according to this view, while the macroeconomic climate continues to slowly improve and corporate earnings should at least stay modestly positive, providing support against sustained drawdowns. However, we do regard our base case view as subject to a potentially more volatile dose of X-factors than normal, and the actualization of one or more of these unknown variables could profoundly impact our assumptions and cause us to reevaluate our expectations. We don’t expect a massive trade war to send the world back into nation-state fortresses of closed economies, for example. But merely having to articulate that this is a not-totally-out-there possibility raises the mercury on our X-factor measuring stick. Things that have simply not mattered much to markets in recent years – geopolitics being an excellent example – may force themselves back onto investors’ radar screens with real consequences. Our recommendation is simply this: plan for the likely, but imagine the unimaginable.