Every afternoon at 2:00 PM Eastern, roughly $3.5 billion in institutional money flows into the market as pension funds and 401(k) contributions get deployed before the close.

Researchers at Duke, Stanford, Notre Dame, and the Nasdaq Economic Advisory Board have studied this pattern. During one volatile week in June, a $1,000 trade set at 2:00 PM settled by 4:00 PM five days in a row, and the full month produced $2,016 in net income on a single contract.