The trader never told his secret and kept it locked away in his safe, but promised his family that they would get it after his death. After his funeral, the heirs gathered and anxiously opened the safe. They expected to find volumes of complicated manuals and formulas. Instead, they were surprised only to find a small slip of paper in the back corner of the safe. Sell corn in December, April, June and September.
Market prices tend to form seasonal patterns that are repeated year after year.
The trader simply used this seasonal pattern. Prices then usually rally into late November or early December after harvest is complete and end users begin needing corn. Prices often fall in January and February as stored crops begin moving to market. Prices then decline as the crop is planted and gets off to a good start in May. Crop problems or dry weather can produce a price rally in late June or early July. Prices typically fall through late July and August as the markets begin to anticipate the coming new crop.