Millionaires have a history of moving to the sidelines ahead of a presidential election, but many among America's wealthy are now moving quickly back into the stock market, knowing that Donald Trump will be president. They told CNBC they are planning big changes to their investment portfolios and a swift change in their outlook on stock sectors.

Millionaires are pouring into financial and industrial stocks and pulling back on tech and health care, which were their favorite sectors in spring 2016, according to the latest CNBC Millionaire Survey, conducted shortly after the election in November.

Thirty-seven percent of millionaires told CNBC that the election results will cause them to make major changes to investment choices, while 40 percent of millionaires said any tax cut will lead to increased investment in stocks.

"A lot of cash sitting idle is now getting back in," said Tom Wynn, director of research at Spectrem Group, which conducts the Millionaire Survey for CNBC. "What they are saying in this survey is that they are investing everything politically. Nothing else is triggering their investments — not age or anything else."

Twenty percent of millionaires said the election will cause them to invest more in stocks, which Wynn said is a high number compared to historical data.