But after crunching the numbers, these widely reported ideas were "just not the case", he said.
"I wouldn't pay any attention to the elections at all and keep my money where it is, based on value fundamentals."
Stangl's research looked at the performance of stocks grouped by industry over a long period of time.
He said previous research had shown that where markets responded to an election, the movement was often short-term and unpredictable.
He cited the example of Ronald Reagan's election in 1980, when the markets were "euphoric" in the short-term.
"If you used the election of a Republican president as a signal to buy defence stocks and hold them for the next four years, would that translate into anything meaningful? The answer is no."
Previous research has shown that, overall, the US stock market performs better under the Democrats by about 9 per cent.
Stangl said he believes the better market-wide performance under Democrats was due to macroeconomic factors that impact stocks from all sectors.
He said investors could consider investing in a market index when a Democrat president was elected, but the best strategy was to ignore the presidential race entirely.