With the annual index rebalancing approaching, hedge funds and traders typically position themselves in late December to avoid the crowded execution window. Historical patterns show that once the funds are absorbed, most rebalancing-related market movements subside by the end of January. The 2026 rebalancing of the BCOM and GSCI commodity indices shows unusually large discrepancies—particularly in cocoa, energy, and grains—and since both rebalancings occur within the same window, the market may experience one of the most concentrated periods of passive commodity flows in recent years. As usual, the January rebalancing has little to do with fundamentals and is more about systemic flows—but the impact on prices could be very real.