Corn Futures Plunge on Rising Stockpiles

Corn futures held below $4.9 per bushel, after dropping over 4% in the previous session to a seven-week low as the USDA's October report projected a larger US harvest and higher ending stocks for the 2026/27 season. The agency raised its yield estimate to 181.2 bushels per acre from 178.5 in September, lifting production to around 16.03 billion bushels. Ending stocks were also raised to 1.849 billion bushels from the previous estimate, reinforcing concerns over ample supplies. Although the USDA increased its export forecast by 25 million bushels to 3.3 billion, the upward revision in production outweighed stronger projected demand. The agency also lowered its season-average farm price forecast to $4.70 per bushel from $4.80. Meanwhile, US corn harvesting was 23% complete as of October 4, below the five-year average of 27%. Rain was expected to return to parts of the Plains and Midwest during October 12–16, potentially slowing fieldwork and delaying farmer selling.

Corn futures fell toward $5 a bushel, pressured by a stronger US dollar and caution ahead of the USDA’s monthly WASDE report due Friday. Prices surged to a one-week high on Tuesday after weekly USDA data showed corn harvest progress and crop conditions below market expectations. Only 23% of the US crop had been harvested by October 4, below the 27% five-year average and 26% expected by analysts; while the good-to-excellent crop rating also fell to 54% from 57% a week earlier, as heavy Midwest rainfall delayed fieldwork. Meanwhile, hot, dry weather earlier in the summer and heavy September rains have added uncertainty over yields and harvest potential, encouraging a wait-and-see approach ahead of Friday’s forecast.

Corn futures rose toward $5.1 per bushel, hitting a one-week high as concerns over delayed US harvesting and weak crop conditions supported prices. Only 23% of the US corn crop had been harvested by October 4, below the 27% five-year average and 26% expected by analysts, after heavy Midwest rainfall delayed fieldwork. The share of the crop rated good-to-excellent also fell to 54% from 57% a week earlier. Export demand remains relatively firm, with 2026/27 shipments running 4.4% above last year at a record pace for this point in the marketing year, despite weekly inspections falling to 1.368 million tones. Elsewhere, Brazil’s first corn crop was 38% planted, slightly behind 40% a year earlier. Geopolitical risks added support, as Russia-Ukraine tensions raised concerns over disruptions to Black Sea grain shipping. Traders now await Friday’s USDA report for updated production and yield estimates, with current forecasts at 178.5 bushels per acre and 15.8 billion bushels of output.