(This story is only for CNBC Pro subscribers)
Many investors are worried that the presidential election won't be settled for some time after Election Day and are trying to position themselves ahead of any political turbulence.
Deutsche Bank analysts studied the few prior elections when the results were contested to help its clients prepare for such a scenario.
The investment bank found that these rare cases — the elections in 2000, 1876 and 1824 — were typically accompanied by bouts of volatility and a flight toward safer assets like U.S. debt.
Former Vice President Joe Biden is widening his polling lead over President Donald Trump, but the concern about a drawn-out result remains with investors hedging for that scenario in the futures market, the bank points out.