US stocks rose slightly last week as the bull market's momentum fed on itself.

Only a fool would bet against another increase in major US indexes this week. The momentum has become a self-fulfilling prophecy. Earnings from the ultimate momentum stocks - Facebook, Amazon.com and Alphabet's Google - are likely to keep the party going.

Nothing, it seems, can wake the bull market from its euphoric daze. Last week, the Chicago Board Options Exchange volatility index, or VIX, hit its lowest level since 1993, meaning that investors are more reluctant to buy insurance on their portfolios than they have been in a generation. And this complacency comes in a year when Donald Trump's presidency has verged on a democracy-rattling legal crisis, when the United Kingdom has verged on political chaos and the Korean peninsula has verged on nuclear war.