No matter the decade or market conditions, impeachments don’t hurt share prices over the long term.

Hard to believe, but true.

Three U.S. presidents have been formally impeached by Congress: Andrew Johnson, Bill Clinton and now Donald Trump.

In addition, two other U.S. presidents have faced formal impeachment inquiries: Richard Nixon (who resigned before the House vote) and Donald Trump. So far, no U.S. president has been removed from office through the full impeachment process.

Here’s a brief look at the returns during that portion of Nixon’s presidency.

Between the start of the Watergate trial, the threat of impeachment, and his resignation, Nixon presided during a drop of nearly 32% in the S&P 500 benchmark stock index, partly due to a recession. And in the 12 months following his departure from the White House, the index recovered more than 5%.

While it’s hard to stay positive in the short term, impeachments rarely have a lasting impact, according to Dan Roccato, president of Quaker Wealth Management in Moorestown.

“Impeachment has a long-term impact on politics, but not markets,” he said. “Traders have the attention spans of a gnat, but investors are better served by ignoring short-term gyrations” and “should always separate politics from portfolios.”

Under Clinton, the stock market was volatile, partly due to the Asian financial crisis in 1998 and the failure of hedge fund Long-Term Capital.

But from the start of Congress’ inquiry until impeachment, the S&P 500 actually rose 23%, and gained 19% more in the 12 months following his impeachment. The U.S. was also experiencing the first boom and an economic expansion.

What about today’s stock market?

The House of Representatives formally launched an investigation and impeachment inquiry into President Trump on Sept. 9.

And during the impeachment inquiry, the S&P 500 wobbled, mostly on concerns about the trade war with China and the potential for a recession in 2020.

But no -- the impeachment hasn’t hurt stock prices one bit. As of Dec. 19, 2019, the S&P 500 has notched an incredible gain of 27.8%

The market continued notching new highs in November and December as worries over Brexit, impeachment, tariffs and slowing growth receded.

For 2020, the second phase of the China trade war will continue. “Don’t conclude that turmoil is a thing of the past,” said Michael Greenly, UBS senior vice president for wealth management, based in center city. “We still think stocks are the best asset class, versus fixed income, for the best returns over the next few years."

With a week or so to go, 2019 is shaping up as one of the best investment years of the decade, as both stocks and bonds have generated positive returns.