Both risk factors are now in play...
"The S&P then infamously crashed in October of 1987, for a variety of reasons, one of which, Barclays suggests, was the rapid pricing in of the Reagan tax cuts."
the "S&P 500 has returned 10% since Election Day while consensus 2017E adjusted earnings have been lowered by 1%"
the "S&P 500 has returned 10% since Election Day while consensus 2017E adjusted earnings have been lowered by 1%"
Regarding small cap outperformance:
The average effective tax rate among S&P companies that had posted calendar fourth-quarter results as of Friday was 24.11 percent — well below the current corporate rate of 35 percent
small-cap stocks will be the biggest beneficiaries from a reduction in corporate taxes and regulations.
Rapid pricing in of tax cuts visualized:
Russell 2000 with Futures Open Interest (black):