U.S. stocks were poised to record their biggest one-day drops in roughly seven weeks on Wednesday, as worries about rising Treasury yields and the potential outcome of the upcoming Nov. 5 presidential election weighed on investors.

Contracts tied to the S&P 500 gained 0.3%. Futures for the technology-heavy Nasdaq added 0.7%. Futures for the Dow Jones Industrial Average were flat before the market opened. Rising bond yields were seen as the culprit for yesterday’s retreat, since higher interest rates on borrowing make those investments more attractive relative to stocks.