Market observers have plenty to be puzzled about as of late. The federal government reverses itself and bails out AIG. The credit markets suddenly dry up, and the Fed issues more liquidity. Then, the feds unleash a plan to bail out billions of dollars in troubled mortgages. Amid this backdrop of financial mishaps, the market is having a tumultuous week, falling dramatically, and then recovering to close the week basically flat. Virtually everyone agrees that the events of the past 10 days are unparalleled, but to explain the reasons behind it is even more problematic. Some market observers and participants...