China must buy roughly $1.2 billion of U.S. agricultural goods per week through the end of the year to meet its prorated purchase commitments. U.S. Trade Representative Jamieson Greer said this week that China has so far purchased around $4 billion of U.S. ag products, leaving about $10 billion of the prorated total outstanding, plus roughly half of the 25 million metric tons of soybeans it committed to buy.

The arithmetic framed Friday's grain trade. Corn and soybeans closed slightly higher and staged an impressive rally off overnight lows after Greer told CNBC that significant progress had been made with China, including on agricultural trade, and that details would be released Monday. Wheat closed lower on talk of a Black Sea grain export corridor.

What pulled buyers back into the market?

Shawn Hackett of Hackett Financial Advisors said Greer's promise of specifics restored confidence after an earlier summit produced none.

"I think the market is looking for headlines, details, you know, things that they've discussed. We got nothing like that last time when Trump went over to China and the market sold off. So with Greer saying they would have some details, justifiably, the markets rebounded back," Hackett said.

Generalities will not sustain the rally, he cautioned. "I don't think generalities are going to cut it. I think we need hardcore details, kind of like what we got back in 2019 when we had specific quantities and a time frame."

The market needs specifics on how much China will buy, when, and which crops — corn, wheat and cotton among the candidates beyond soybeans. Hackett also wants to see Beijing drop its 10% reciprocal tariff on grains and soybeans. "I think it's important that these tariffs drop and then they show their hand... that they are going to purchase other products beyond soybeans," he said.

Does China's purchase framework resemble Phase One?

Hackett expects a Phase One-style structure, with defined quantities for crops beyond soybeans.

"It'll be for corn. It'll be for wheat. It'll be for other markets now that we can define how much, when, and then we can start monitoring. Are they living up to what they agreed to?" he said.

Buying in volume would push prices up against China's own interests, but Hackett argued current prices remain attractive and that Super El Nino worries are driving Beijing to stockpile. Southern China has faced endless typhoons and flooding, while drought has hit the central plains, raising doubts about domestic crops. "Better to have more birds in the hand than in the bush at this point," he said.

He expects China to exceed its commitments. "I actually think we're going to see them expand what they agreed to... much more akin to what we saw during the first term of President Trump when we had much more of a broad, defined, ag market purchasing program than just some isolated benchmarks," he added.

Why are soybean basis and yields in play?

Strong cash basis of up to $2 over the board in the western Corn Belt, where rain has delayed harvest, is supporting soybeans. "Processors are out of soybeans, they desperately need them, they can't wait to buy them," Hackett said.

He expects yield losses from the wet harvest to trim final soybean numbers by half a bushel to a bushel below current USDA estimates. With carryout near 300 million bushels, that would draw supplies down to pipeline levels and set up what he called an "epic" acreage battle for next summer, with corn, cotton and rice all competing for limited U.S. acres.

Corn and soybeans closed back above key technical support Friday — $13 November soybeans and $5.25 December corn. "Historically these kind of demand-led markets ended with a $7 to $8 corn market," Hackett said, noting the European corn crop is the worst in 50 to 100 years and Super El Nino typically hurts Brazil's safrinha corn.

Wheat fell despite Black Sea corridor talk; Hackett estimates Black Sea exports will run 50% below normal on alternative routes alone.

What did livestock do?

Cattle futures closed mostly higher and posted higher weekly closes despite ICE raids at Kansas packing plants that slowed Friday slaughter to 87,000 head, and the reopening of a second southern port at Santa Teresa, New Mexico, where only 400 Mexican cattle crossed Thursday. The Cattle on Feed report showed record-low August placements, signaling tight supplies. Hackett sees the market holding above $210 support and likely range-bound short term.

Lean hogs fell despite a positive USDA Quarterly Hogs and Pigs Report showing contracting numbers. "The market just continues to be disappointing... the commercials have zero interest in selling this market, which usually means the market's at a low. But it's been very sluggish trade," Hackett said.

Traders now await Monday's release of the China trade details, which will determine whether grain markets sustain Friday's rebound or repeat the selloff that followed the last summit.