Sure, Friday ended up being a broadly positive day for risk assets, with hopes rising of a deal to resolve the US budget crisis.
Shares were 0.5% higher in Wall Street in late deals, having closed 0.9% higher in London, and seen even stronger performances in Asia.
However, the situation in commodities was more nuanced, with many decliners – and not just gold, whose status as a safe haven investment left it down $16 an ounce to $1,269 an ounce, its lowest for nearly three months.
The CRB commodities index indeed dropped 0.3%.
Complicit in that decline was corn, which felt the continued pressure from open harvest weather and promising yield reports.
Macquarie pegged the US corn yield at 158.1 bushels per acre, above the 155.3 bushels per acre the US Department of Agriculture has factored in.
It was also above the 156.5 bushels per acre that the USDA was expected to upgrade its forecast to today - had it not been on data blackout, thanks to the US government shutdown, which prompted it to postpone its monthly Wasde crop report.
The bank its research showed "Illinois, Indiana and Ohio showing the highest results, at above 170 bushels per acre.
"These numbers are much higher than those we had observed in late August-early September, when the harvest was considered to be under threat from dry weather."
'Path of least resistance'
Darrell Holaday said: "The corn and soybean markets have been trying to wrestle and deal with much better than expected yields and a wide open harvest week.
"With that situation the path of least resistance has been lower."
And the corn market continued to feel pressure too from ideas that the Environmental Protection Agency will cut the level to which US blenders must mix ethanol into gasoline to 13bn gallons, from a 2014 figure of 14.4bn bushels which had been proposed .
"This does not mean that that the industry cannot blend more than 13bn gallons, but it will have to make its way into the blend with price only," Darrell Holaday said, estimating that 520m bushels in corn demand had been lost.
(Other commentators calculated the loss at 200m bushels, although that may in part have been down to using the 2013-14 marketing year, rather than calendar 2014.)
'Stars lining up negative'
Whatever, it means stocks, already expected to be huge at the end of 2013-14 (Informa on Friday pegged than at 1.94bn bushels) look like being even bigger than had been expected,
At Chicago broker RJ O'Brien, Richard Feltes said: "The stars are all lining up negative – a big harvest weekend, ongoing favourable yield reports, the proposed EPA cut in the corn ethanol mandate, players heading to the sidelines on the USDA news blackout and investors' rush to equities…"
Chicago corn for December dropped 1.1% to close at $4.33 ¼ a bushel, the lowest finish for a spot contract for three years.
'Concerns were exaggerated'
Some of the same pressures, of open harvest weather, and generally encouraging yields for farmers, played against soybeans too.
For soybeans, "concerns about the drought impact this year were exaggerated as rains in June helped crops to survive the subsequent dry August, by boosting sub-surface soil moisture", Macquarie said, if estimating the yield at 41.3 bushels per acre, less than some other figures which have been flying around.
The current USDA figure is 41.2 bushels per acre, and analysts had expected to Wasde, had it happened, to lift that to 41.5 bushels per acre.
Not so bullish…
There was an extra dynamic going on with the EPA biofuel proposals too, with some of the 1.3% gain in soyoil in the last session apparently due in part to an idea that a figure for 1.28bn gallons for blending of biodiesel (largely made from the vegetable oil) next year was bullish.
"Biodiesel would actually go from 1bn gallons to 1.28bn gallons," Darrell Holaday at Country Futures said.
"On the surface the biodiesel number may seem supportive to soybeans, but the market was actually planning on growth well beyond the 1.28bn-gallon level."
Soyoil lost all the last session's gains, and more, closing down 2.3% at 40.28 cents a pound in Chicago for December delivery, with a decline in Kuala Lumpur palm oil, down 0.5% at 2,380 ringgit a tonne in its first negative close in six sessions, adding further pressure.
November soybeans shed 1.7% to $12.66 ¾ a bushel – the lowest finish for a spot contract in nearly 20 months.
It was left to wheat to uphold bulls' hopes, adding 1.0% to $6.92 ¼ a bushel in Chicago for December delivery – so lifting its premium to corn nearly to $2.60 a bushel.
Some of the same forces were at work, with Benson Quinn Commodities noting that "weather concerns in South America and the Black Sea still offer support to the wheat market".
In fact, prices in Argentina have gone to $500 a tonne or more, thanks to the weakened harvest prospects there, after depleted 2012 production too.
(And Egypt's Gasc was on Thursday complaining at being asked to pay prices which for Romanian wheat were less than $275 a tonne, excluding freight.)
The United Nations Food and Agriculture Organization last week highlighted the huge increases in flour prices in Argentina, and in the likes of Brazil, where they have reached a record high, and Paraguay too.
Meanwhile, although Egypt was deterred from the market by high prices, Japan bought on Friday, 101,892 tonnes of food wheat from Australia, Canada and the US, while Morocco tendered (again) for 330,000 tonnes of European wheat.
Sure, India returned to exporting sales for the first time since August, selling 30,000 tonne of milling wheat to the United Arab Emirates, but the price of $285-315 a tonne did not look over-competitive.
Furthermore, the Australian harvest has begun with decent volume ideas but disappointing protein results – touching a raw nerve for markets where, thanks to rain damage to crops in Brazil, China and Russia, quality has become a key factor.
In Paris wheat for November closed up 0.2% at E199.25 a tonne, while London wheat for November added 0.2% to £163.00 a tonne, nonetheless, enough to give the lot the best finish for a spot contract since July.
Ethanol vs sugar
Among soft commodities, raw sugar extended its rally on ideas of setbacks to the Brazilian Centre South crush from rains, concerns confirmed in a report on Thursday from cane industry group Unica.
New York's March contract closed up 1.1% at 18.93 cents a pound, the highest for a spot contract in nine months.
Nick Penney, senior trader at Sucden Financial, noted that "millers show that they are now favouring ethanol production more, and specifically anhydrous production possibly anticipating an increase in the anhydrous content of gasoline".
Meanwhile, Brazil's government has signalled that Petrobas can increase the Brazilian gasoline price by about 6%, a positive signal for hydrous ethanol (an alternative to gasoline, rather than an additive).
'Good selling points'
Cocoa set a fresh two-year high in London by adding 0.8% to £1,779 a tonne for December, helped by continued hopes for the current round of grinding data, and by weather concerns.
"The much-needed rains in West Africa are now here, but this is delaying harvesting, at a time when grinders are desperate for new supplies," Macquarie said.
And arabica coffee added 2.0% in New York to 116.70 cents a pound for December delivery, although not all observers remained convinced by the rise.
"Rallies in this market will continue to be short-covering only, and prove good selling points," Volcafe said.
Judith Gaines-Chase, at J Ganes Consulting, raised the potential for huge Colombian production in 2013-14, despite a caution to farmers from the South American country's government not to overdo production and worsen pressure on prices.