BofA's Hartnett: a Democratic sweep could knock stocks 10%+

Hartnett flags election risk for stocks

Bank of America’s chief equity strategist, Hartnett, says a Democratic sweep could push stocks down 10% or more, according to MarketWatch. His warning frames the election outcome as a significant risk for equities.

The report, published Oct 9, 2026, at 2:54 PM ET, puts the probability of a Democratic sweep at 64% in betting markets. That is up from under 50% a month ago.

A conditional warning

The sweep scenario concerns Democratic control of Congress, according to MarketWatch. The rise to 64% places that outcome above even odds, but still leaves substantial uncertainty.

Hartnett’s warning is conditional: the potential stock decline is tied to a Democratic sweep, rather than presented as an unconditional market forecast. The available summary does not specify a stock benchmark, a timeframe for the potential decline or which betting markets supplied the probability.

What it means for prediction markets

• Election odds have shifted: The move from under 50% to 64% represents an increase of more than 14 percentage points in a month.
• The probabilities measure different things: The 64% figure concerns a Democratic sweep—not the likelihood of a stock decline of 10% or more.
• Contract details remain unavailable: Without the underlying market names or resolution terms, the reported probability cannot be mapped precisely to a particular prediction-market contract.