Traders are anticipating the largest Fed-Day move in the S&P 500 since 2023, according to Citi. Options professionals are preparing for a significant swing in the S&P 500 following the upcoming FOMC meeting, with the index having dropped 4.2% in April due to concerns over geopolitics and rates. The market is implied to move 0.95% on Wednesday, suggesting a substantial reaction to the interest-rate announcement.