New York Times:  Tax Increases and Bull Markets, by  Bruce Bartlett:

[T]he stock market rose sharply
after the passage of the tax deal,  which raised the top income tax
rate and the rate on capital gains and dividends. This is the opposite
of what should have happened according to Republican doctrine, which
holds that the tiniest increase in tax rates, especially on the rich, is
economically devastating. That got me thinking about the impact
of other tax increases in history.

A little research showed that sharp
increases in the stock market have often followed big tax increases. … I have long suspected that when
tax rates are low they make it too easy for investors to get an adequate
after-tax return. When rates rise, they must work harder for a higher
before-tax return to compensate for the higher taxes. This pushes money
into growth sectors.

I’m not prepared to predict that the great
bull market of the 2010s began on Jan. 2. But I do know that anyone who
thinks tax increases never precede a bull market is wrong. History
proves that.