The March contract backed off its highs by the close, settling up only 1/2 cent at $5.52-1/2. Even so, prices were up about 10 percent since the contract settled just under $5.00 two weeks ago.
"We've had a 50-cent run-up in the board, and that's what a lot of people were waiting for," said Greg Johnson, a grain buyer with The Andersons Inc in Champaign, Illinois.
"We bought quite a bit here Wednesday, Thursday and Friday. We've had a pretty good run, although today was the heaviest by far," he said.
The influx of cash soy sales pressured the CBOT March/May spread, which weakened by 2-1/4 cents, CBOT traders said.
The movement also weighed on cash basis bids, which fell 3 to 5 cents in major soy processing sites including Danville and Decatur, Illinois, and Des Moines, Iowa.
Johnson estimated that his facility bought close to 100,000 bushels of soybeans on Friday, four to five times the volume of a typical day.
In West Des Moines, Iowa, merchandiser Wade Entriken of Heartland Co-op estimated that the co-op's 28 grain elevators took in about 200,000 bushels of soybeans, four times the average day's take, as farmers seized on a pricing opportunity.
"They are taking advantage of this run-up in beans to catch up on some old-crop pricing, and start in on some new-crop pricing," Entriken said.
The jump in soybean sales was not limited to the United States. "There was big movement both here and in South America," one cash-connected CBOT trader said.
US farmers harvested a record 3.1 billion bushel soybean crop last fall, but they grew reluctant to sell much of it through the fall and winter as soy prices tumbled from a near-16-year-high last spring at $10.64 per bushel.
Analysts had also projected a record soybean crop in Brazil, the world's No. 2 producer after the United States.
But forecasts this week for dry weather in Southern Brazil sent CBOT soybean futures soaring as traders weighed concerns of crop stress in the states of Rio Grande do Sul, Parana and southern Mato Grosso. US markets will be closed on Monday for the Presidents Day holiday, and crop weather in Brazil over the weekend was expected to be the key factor in Tuesday's price action, cash grain merchants said.