Crops traded lower in midday trading in Chicago, as concerns over China's rate rise continued to prompt concern, with the prospect of a regulatory ruling on position limits giving investors another reason to fret.
But losses were limited by some weakness in the dollar, following disappointing US jobless data. The Commerce Department said that 85,000 jobs were lost in December, far higher than the 10,000 or so that analysts had forecast.
The euro rose back above $1.44 at one stage, improving the attractions of dollar denominated exports, such as crops, to European buyers.
And another prop was, of course, the prospect of fund rebalancing, an annual process which sees commodity funds adjust position limits back to base levels – meaning 2009's laggards, such as grains, get bought, and the stars, such as sugar and copper, are sold.
"The index fund rebalancing is expected to start in earnest late in the session and this could cause a lot of short-covering later in the session, especially in corn," Vic Lespinasse at GrainAnalyst.com said.
Benson Quinn Commodities said: "Today is the first day of rebalancing by some index fund who are expected to buy 10,000 to 12,000 contracts of corn each day for the next five days."
Such thinking was backed up by US Commodities, which said: "The trade anticipates 10-15,000 contracts of corn to be purchased daily by the Goldman Sachs fund as they rebalance [over] the next five days."
While there was not much evidence as funds getting involved as of 17:00 GMT, nor was there any certainty that they may not later on.
"It might prove to be a waiting game today as traders try to figure out how much impact, if any, index fund buying will have late in the session," Mr Lespinasse said.
And there were, otherwise, reasons to sell, notably continued concerns over China's rate rise at a sale of three-month bills on Thursday. If China cools its economy, commodity markets may freeze, the thinking goes.
And soybeans, the main target of Chinese buying, slid 6 cents in Chicago to $10.20 a bushel for March delivery, with the soon-to-expire January lot off 6.5 cents at $10.11 ¼ a bushel.
Not that all the complex was so affected. The cold weather gave investors reasons to buy soymeal, a livestock feed, which will be in greater demand thanks to the cold temperatures, which will leave cattle needing to eat more to maintain body temperature.
Soymeal for March stood 0.2% higher at $298.70 a short ton.
Similar thinking may have been a factor relative strength in wheat too, with March wheat down 0.5 cents at $5.49 ¾ a bushel and March corn down 2 cents at $4.15 ½ a bushel.
Still, if bears needs sustenance, the prospect of positions limited set to be announced on Thursday by US regulators provided some.
There has been concern in the US about the impact of index funds on skewing markets, and in particular provoking a disconnect between cash and futures prices.
"If index funds are subject to these newly imposed position limits, this could have a bearish impact on all commodities, including grains," Mr Lespinasse said, pointing out that funds like to keep a relation between commodity weightings.
"If they can't freely invest as much as they want in energy and metals, they wouldn't be able to put additional money into other commodities such as grains either."
Still, Benson Quinn was sanguine, expecting the Commodity Futures Trading Commission to announce "generous position limits".