By Kirk Maltais

--Wheat for December delivery rose 2.6% to $5.56 1/4 a bushel on the Chicago Board of Trade on Thursday, as funds continued to pile into grains futures amid indications of higher Chinese demand.

--Soybeans for November delivery rose 1.7% to $10.28 1/2 a bushel.

--Corn for December delivery rose 0.9% to $3.75 1/4 a bushel.

HIGHLIGHTS

Finding New Highs: Corn, soybeans, and wheat closed at recent highs. "Optimism that Chinese buying will continue has the bears reluctant to press the short side of the corn market," said Tomm Pfitzenmaier of Summit Commodity Brokerage. Corn is at the highest price it has traded at since March, wheat is at its highest since April, and soybeans has reached a more than two-year high.

Big Tonnages: Soybean sales for the 2020/21 marketing year totaled 2.46 million metric tons for the week ended Sept. 10, according to the USDA. That's in line with the expectations of traders surveyed by The Wall Street Journal, which forecasted anywhere from 1.5 million tons to 2.8 million of tons of soybeans to be sold. As expected, China was the main buyer, purchasing 1.49 million tons. According to grains traders, China's appetite for soybeans is likely due to attempts to rebuild decimated hog herds. The USDA also confirmed that more soybeans have been sold to China, announcing a flash sale of 264,000 metric tons. That makes 852,000 tons of beans announced sold to China this week.

INSIGHT

China Effect: Weather issues in China have increased interest in U.S. corn, analysts say. "Private analysts think Chinese corn production is down 5 million metric tons more than the USDA has accounted for, so Chinese supply is also feeding the bull story," said Craig Turner of Daniels Trading. "On the demand side the Chinese hog population is expanding rapidly and the need for feed is real. Add all this together with the Phase One trade agreement and it makes sense for China to buy U.S. ag products aggressively."

Off the Starting Block: The U.S. grains harvest is expected to begin in earnest this weekend and ample supplies are expected to hit the market soon. Whether this slows the recent rally in grains remains to be seen. Activity is also expected next week "with producers just starting to aggressively cut corn," AgResource said. The USDA's weekly crop progress report on Monday will be watched to see how the harvest has progressed. In its last report, the USDA pegged the U.S. corn harvest at 5% complete, with soybean harvest figures not yet released.

AHEAD

--The CFTC releases its weekly commitment of traders report at 3:30 p.m. ET Friday.

--The USDA releases its weekly grain export inspections data at 11 a.m. ET Monday.

--The USDA releases its weekly crop progress report for the 2020/21 crop at 4 p.m. ET Monday.

Write to Kirk Maltais at kirk.maltais@wsj.com