S&P 500 futures liquidity has sharply declined to $5.1 million, marking a 61% drop below the historical average of $13 million, according to The Kobeissi Letter. This level of liquidity is approaching the lowest since April 2025's "Liberation Day." Goldman Sachs data suggests that liquidity below $7 million indicates market stress. The current low liquidity environment means that large orders can significantly impact the S&P 500, reminiscent of the volatility seen during the 2025 tariff announcement. This situation heightens the influence of institutional trading and suggests potential for extreme market volatility.