Many financial markets have taken fright at the prospect of, another, showdown in Washington between legislators over how to balance the US budget.
Asian share markets were, broadly, lower, with Shanghai stocks shedding 1.9% in late deals, although Tokyo's Nikkei did put in a late recovery.
For grains, however, Thursday brought a firm start, if not spectacularly strong, as Chicago wheat took aim at a fourth successive higher close for the first time since July.
'Heat and moisture stress'
Oats were in fact the strongest pit, adding 1.4% to $3.18 ¼ a bushel for December delivery, as some concerns emerge over the Canadian grains harvest.
Gail Martell, at Martell Crop Projections, has highlighted damage to Saskatchewan crops from "heat and moisture stress" thanks to dryness extending from late July to earlier this month.
August was incredibly dry with no rain in Saskatchewan's northern wheat districts," Ms Martell said, adding that "a late summer heat wave further stressed wheat, rapidly advancing crop development".
In wheat, a Saskatchewan survey has shown yields from 35-42 bushels per acre, below the 44 bushels per acre forecast by Statistics Canada.
'Rethinking their position'
And oats are, according to Chicago lore, a leading indicator for other grains – "oats knows", the phrase goes.
Certainly, wheat managed another positive start, adding 0.4% to $6.73 a bushel for December, building on what Brian Henry at Benson Quinn Commodities termed "just enough chatter about potential demand and possible global quality issues".
This has the "net short fund community in Chicago and Minneapolis rethinking their position", a reference to the extensive short holdings which some brokers, including Benson Quinn Commodities, flagged earlier this week would likely support prices.
'Sign of value'
The quality issues have concerned most recently Argentina, the southern hemisphere's second-ranked wheat exporter, where dryness and frost have challenged crops.
"The potential that a frost occurrence in Argentina may hurt the wheat crop has driven prices higher," CHS Hedging said.
And that has only increased ideas that Brazil, which typically buys from Argentina, will be forced to turn further north to shore up its own supplies, which have been weakened by its own harvest setbacks from frost, and now harvest-time rains.
Mr Henry highlighted Brazil's "continued interest in US hard red winter wheat", as traded in Chicago, which he said was also "sign of value" in the crop, implying scope for higher prices.
Furthermore, there are a stack of rumours about China purchasing too, from the US and/or Argentina and/or Australia, although with orders for soft wheat, as traded in Chicago, the focus of rumours.
Certainly, benchmark January wheat futures on China's Zhengzhou exchange gained overnight, not quite touching Tuesday's contract high, of 2,885 yuan a tonne, but closing up 0.5% at 2,857 yuan a tonne nonetheless.
In cash markets, "Chinese wheat prices are at record highs due to dwindling high-quality supplies and growing expectations that state purchase prices will rise before the planting season begins," CHS Hedging noted.
More will be known on US exports later, with weekly sales data expected to come in at 500,000-700,000 tonnes.
'Showing positive momentum'
Technicals on wheat have improved too, with the December contract in the last session closing above its 75-day high for the first time in three months, having achieved a similar feat for the 50-day line the session before.
On the continuous chart, the December contract closed above the 100-day line too, the first time for a spot contract in 10 months.
"Technical studies of all types are showing positive momentum," Mr Henry said.
One potential chart hurdle is the late-August high of $6.76 ½ a bushel, which the contract baulked at in the last session and on Thursday too.
The lot hit $6.74 ¼ a bushel before easing a touch to $6.74 a bushel as of 09.10 UK time (03:10 Chicago time), still up 0.5% on the day.
Wheat vs corn
With wheat higher, that gave a pull to corn too, given that the latter grain is at an unusually large premium.
"The wheat market is slowly but surely divorcing itself from the feed grains as stories regarding non-traditional demand for US wheat are causing enough of a stir to limit the aggressiveness of potential sellers," Mr Henry said.
Still, the premium of well over $2 a bushel is being noted by corn investors, who have a large net short in this grain too.
That is helping investors overlook, for now, continued talk of higher-than-expected US corn harvest results.
"Yield progress continues to gain speed everyday with promising early yields," CHS Hedging said.
Joyce Liu, at Phillip Futures, said that "the release of better-than-expected corn yields as well as expectations of a record large corn output this year could pressure corn prices going forward".
Furthermore, Lanworth on Wednesday raised its forecast for the world corn crop in 2013-14 by 7m tonnes to 949m tonnes, including estimates for Argentina of 28.2m tonnes and Brazil of 75,9m tones, above the US Department of Agriculture forecasts of 26.0m tonnes and 72.0m tonnes respectively.
Corn for December stood up 0.1% at $4.55 a bushel, although its direction later could be determined by US weekly export sales data, which investors expect to come in at 400,000-600,000 tonnes.
Huge sales figure
For soybeans, US weekly export sales are expected at a mammoth 2.3m-2.8m tonnes.
But that does include 1.93m tonnes of sales already announced to China.
And soybeans too faces pressure from the build up in the US harvest, which is already pressing on the cash market, yet, as an oilseed, their futures do not have such direct positive support from strong wheat values.
Furthermore, hedge funds do not have a net short position in the oilseed to worry about, having a hefty net long in fact
'Struggling to get soybeans planted'
Sure, the newsflow on the oilseed is not all negative
CHS Hedging noted that early reports from the US harvest "are better than expected, but there have been select producers that are disappointed".
Furthermore, "South America is struggling to get soybeans planted, with many areas being dry", although it is still early days in the planting season.
And in Argentina, "soybean growers are reluctant sellers, as they wait for election results near the end of October".
Still, soybeans for November eased 0.6% to $13.14 a bushel.
'Risk premium being removed'
Among soft commodities, cocoa extended its decline on profit-taking, and rains which have boosted hopes somewhat for the important West African crop.
"The risk premium associated with the unfavourable weather in Ivory Coast is now slowly being removed as the main harvest is soon approaching and the rain in Ivory Coast continued to boost soil moisture," Ms Liu said.
Cocoa for December eased 0.4% to $2,562 a tonne in New York.
But cotton for December edged 0.4% higher to 84.95 cents a pound for December after China confirmed a lower harvest, with a farm ministry official quoted as forecasting a 5.1% drop in production to 6.315m tonnes.
China is the top cotton producing country, as well as the biggest consumer and importer.
The China Cotton Association has pegged the crop at 6.93m tonnes.