There is a theory that, in times of market stress such as this, correlation between price movements of different commodities grows.
Investors are seen as adopting broad "risk on" or "risk off" strategies, rather than discerning differences between raw materials and their fundamentals.
If that observation is to prove true this week, wheat should be on for a storming performance.
For three-month London copper added a further 1.5% in early deals on Friday, to take its gains for the week nearly to 5%.
As of 07:15 GMT (08:15 UK time), Chicago's benchmark December wheat contract was up 0.5% at $6.18 ¾ a bushel. Sure, that reversed some of its losses of the last session, but took its gains for the week to a miserly 1.6%.
And both faced a broadly improved macro-markets picture, with the Nikkei
As an extra sign of risk-on sentiment, the Vix gauge of fear closed Thursday down 4.1% at 36.27 points, with 40 being seen as an alarm bells level.
But wheat's problem is, well, rain for drought-hit US hard red winter wheat districts is one, although it is not clear how much precipitation will fall.
"Rain is forecast in the dry hard red winter wheat belt today and over the weekend, contributing to the bearish mood," Luke Mathews at Commonwealth Bank of Australia said,
"But the dry bias is expected to return thereafter according to most forecasters."
At Benson Quinn Commodities, Brian Henry said that regions west of a line running from central Nebraska to the Texas panhandle "will continue to struggle with dry conditions", although areas would at least see cooler temperatures.
Another is the prospect of the US Department of Agriculture's monthly crop estimate updates, summarised in its Wasde report, due on Wednesday, which has spawned the latest wave of crop yield updates.
(Linn Group on Thursday raised by 1.2 bushels per acre to 42.2 bushels per acre its forecast for the US
"Traders will be eyeing the Wasde report to see if the USDA is expecting demand destruction in the agri complex," Mr Mathews said.
Indeed, that was seen as one reason why wheat's Chicago peers were even more reluctant to exploit the better market mood – harvest pressure being another.
"Traders will probably remain cautious of extending risk in the face of an expanding harvest, particularly without a supportive fundamental feature," Lynnette Tan at Phillip Futures said.
Weather in the Midwest has remained dry for, speeding the harvest and raising some questions over storage, even if looking wetter in the south.
Corn for December dipped 0.5% to $6.02 ¼ a bushel, while soybeans for November eased 0.5% to $11.58 a bushel.
In Kuala Lumpur,
Indeed, the drop are seen as leaving palm oil with an unusually large discount to rival
And in New York,
"Poor demand remains the most significant headwind to cotton values," Mr Mathews said.
The fibre also faces potential technical resistance at 104.43 cents a pound, its 50-day moving average.