"The short squeeze in the May corn contract has become one of the most dramatic inverses in history," Mr Holaday said.
Rival broker US Commodities noted that corn prices on China's Dalian exchange closed overnight "near record highs", and at the equivalent of more than $9.60 a bushel, with soybeans priced above $19.20 a bushel.
Indeed, the USDA also confirmed export orders of 216,000 tonnes of soybeans, half to China - the day after releasing weekly sales figures which, at 1.4m tonnes, trounced market expectations and stoked expectations of an upgrade to trade forecasts.
Friday's sales were actually for soybeans from this year's harvest, taking total commitments for 2012-13 so far to 8m tonnes, four months before the marketing year even begins, and before most of the crop has been sown.
Indeed, the level of advance orders is a record at this stage, and equivalent to roughly 20-25% of what the US might expect to ship during the season.
The appetite for importers to book so far ahead reflects a disappointing South American harvest, which is continuing to attract downgrades following frost in Argentina, which has further damaged unharvested crops tested already by drought.
Frost has also hit parts of the US, representing a serious threat to winter wheat crops which, thanks to an unusually warm start to spring, have developed some two weeks ahead of schedule.
"A hard freeze developed overnight in key Midwest wheat states - Ohio, Michigan and Indiana," Gail Martell, at Martell Crop Projections, said, noting that 19% of wheat in Indiana had reached the headed stage of development.
Rice Dairy's Mr Gidel said: "When wheat gets to the jointing stage it needs some four hours at 28 degrees Fahrenheit or less to damage it. When it is headed, it just needs about 30 Fahrenheit for a couple of hours."
Ohio, Michigan and Indiana between them produce some 30% of soft red winter wheat, the type traded in Chicago, and areas further south growing hard red winter wheat, as traded in Kansas, may be hit by the next wave of frost this evening.
Ms Martell said: "Temperatures may fall into the low or mid 30s Fahrenheit tonight in north west and west-central Kansas," adding that "adjacent wheat areas in Colorado and western Nebraska also may be subject to frost", if not as severe a freeze as that which hit the Midwest states last night.