Would the late fall to earth in wheat prices in the last session set the tone for Friday's trading?
Certainly, wheat, the market leader in the grain and oilseeds complex of late, struggled in early deals, in part thanks to a broader concern, and in part to a specific one.
The wide-ranging fear is that the absence, because of the US government shutdown, of US Department of Agriculture data - seen as source of market transparency, a force against market manipulation – investors will shut up shop and go avoid the agricultural commodity markets.
The absence of "fundamental data has many traders moving to the sidelines", Kim Rugel at Benson Quinn Commodities said.
"If not necessarily leaving the market, the speculator is not adding to new positions with Thursday's volume down from Wednesday's."
'Sizeable market moves'
And even if investors can cope with the current statistical void, can they cope with a "data dump" when the USDA does come back onstream (and online)?
This torrent of numbers "could trigger sizeable market moves, similar to volatile market reaction to recent quarterly corn stocks updates", Richard Feltes at broker RJ O'Brien said.
"The potential for elevated price volatility later this month is increased –a reality that may push selected players to the sidelines."
More specifically for wheat, there are ideas that Brazil, whose import demand has been a major prop to US prices, may be looking elsewhere for grain too.
Besides rumours that Brazil is continuing to show interest in US hard red winter wheat, there are "rumours that they have begun to get more serious about low protein Canadian spring wheat", Benson Quinn Commodities said.
US Commodities said: "South America may buy hard red spring wheat out of Duluth versus hard red winter wheat," which even if it means US grain, would shift the focus from Kansas City (hard red winter wheat) contracts.
Sure, it looks like Argentina, Brazil's typical source of export supplies, is out of the running, after frost and drought damage to its crop (as highlighted by the UN Food and Agriculture Organization) and talk that President Cristina Fernández could introduce export restrictions as a populist, inflation-busting move ahead of elections on October 27.
But, according to Mr Feltes, Brazil could also source some of the 5m tonnes of imports it needs in 2013-14 from Germany, Europe's flagship producer of hard winter wheat.
'Is it sustainable?'
As an extra reason for wheat investors to think twice about raising prices further, there is the hefty premium that it already has compared with fellow grain corn, a rival for uses such as feed.
"The markets have firmed over the week, but is it a sustainable rally?" David Sheppard, managing director at UK merchant Gleadell said.
"Chicago wheat is currently priced at an $80 premium to corn, an unrealistic figure.
"With corn values likely to decline through the harvest, the likelihood is that, as more new crop US corn enters the supply chain, the current corn/wheat premium will have to break."
Some investors had second thoughts allowing December (soft red winter) wheat, which has gained on eight of the previous nine sessions, to ease 0.25 cents in Chicago to $6.89 a bushel as of 09:15 UK time (03:15 Chicago time).
Kansas hard red winter wheat did better, adding 0.1% to $7.56 a bushel for December, and Minneapolis spring wheat gained 0.2% to $7.52 a bushel.
Still, corn was not letting its discount grow, gaining 0.1% itself to $4.39 ¾ a bushel for December, as investors took the opportunity to take profits on some of their huge short positions.
Concerns over rain delays to the harvest, short-term at least, offered some support.
That said, the overwhelming consensus is of a huge US crop which will continue to weigh on prices, with increasing mention that a value beginning with a $3 is in the offing.
"Market confidence about a US corn yield approaching 160 bushels per acre is increasing, which suggests a 14.0bn+ bushel crop, even with 1m less harvested acres," Mr Feltes said.
'Looks dumb to buy, but…'
For soybeans, the picture of harvest pressure is nuanced by a seasonal tendency for prices to rise at this time of year.
"Usually buying soybeans the first week or two of October is a seasonal play," Mike Mawdsley at broker Market 1 said.
"It typically looks dumb to buy, but just when it looks the dumbest, it can be the best buy opportunity."
And certainly, the complex is gaining support from a firming soymeal basis, and concerns, exacerbated by harvest delays, over whether there is enough crop around to meet demand, with supply levels still suffering a hangover from last year's poor harvest.
'Timing is everything'
But it has not gaining enough support to prevent prices falling 0.3% to $12.84 ¼ a bushel for November delivery.
Mr Mawdsley noted that "we are usually advanced more than we currently are harvest-wise.
"My best guess is we'll find at least a short-term bottom sometime this month - but timing is everything."
And there is also some expectation that the oilseed may find support from Chinese demand, once the top soybean importing country returns from holiday on October 7."
Among soft commodities, cocoa opened weak in London, down 0.2% at £1,660 a tonne for December delivery, after in New York suffering its biggest losses in more than a month in the last session.
"It seemed that cocoa reacted less to fundamental news," Joyce Liu at Phillip Futures said, noting Ivory Coast's decision to raise the guaranteed minimum price for farmers for the chocolate ingredient.
Furthermore, next week will bring European cocoa grind data for the July-to-September quarter which many expect to show a strong a number, in addition to ideas "of grind numbers being adjusted higher due to revisions after discrepancies in the previous quarters".
Arabica coffee rose 0.4% to 115.70 cents a pound in New York for December delivery despite a forecast from the Colombian coffee growers' federation that domestic output will return above 10m bags this year.
Output for the first nine months of 2013 was, at 7.6m bags, up 40% year on year.
Colombia's coffee output has suffered a long downturn, depressed by an outbreak of roya fungus and the impact of replantings with trees resistant to the disease, but which are only now becoming mature.