The last day of the month is, by Chicago tradition, a time when funds close many positions, tidying up their books.
Was this a reason why wheat prices rose again? After all funds are largely short in Chicago wheat, meaning that position closing could foster gains in the grains.
Certainly, many analysts are puzzled by the grain's ability even to hold its own, let alone recover nearly 10% from a January low despite the prospect of a huge rebuild in inventories in 2011-12, and prospects not bad for next season too.
"Based on global and domestic supplies, I still contend that the easy money is going to be made on the short side of the wheat market," Brian Henry at Benson Quinn Commodities said.
"The prospects of profit-taking resistance are high, if the dollar strengthens."
Mike Mawdsley at Market 1 said: "I still can't find anything wildly bullish the wheat fundamentals."
At Phillip Futures, Lynette Tan said: "Wheat's fundamentals remain questionable."
However, there are technical reasons for support.
"With front-month Chicago prices on the verge of topping their 200-day moving average, more upside is possible," Ms Tan said.
Taken on a rolling-contract basis, rather than the March lot itself, the 200-day moving average is at $6.89 a bushel, less than $0.20 away.
And Mr Mawdsley highlighted the scale of investors' bets already on falling Chicago wheat prices. "Remember funds are huge shorts, and just buying back short contracts can give us pops in wheat from time to time."
Whatever, Chicago's March lot managed a gain of 0.6% to $6.66 ¼ a bushel as of 08:40 GMT, on what was too a decent day for risk assets, with many gaining in part thanks to the prospect of the European Central Bank offering cheap loans to prop up eurozone banks.
May wheat added 0.3% to $6.70 ½ a bushel, although interestingly May contracts lagged in Kansas and Minneapolis, where speculators have not put in such huge short positions.
Corn was a touch higher too, helped by continued talk over the prospect of demand from China, where corn for September added 0.6% to 2,421 yuan a tonne on the Dalian exchange.
"The bullish side of the complex is still expecting fresh Chinese demand to surface as their domestic prices are continuing to escalate," Benson Quinn's Jon Michalscheck said.
"It didn't help that China's agriculture minister expects that their all-grain production could decline by nearly 8% this year due to an increased in input costs and possible weather concerns," a reference to the report of a state radio report that the country's grain output may fall to 525m tonnes this year, from 571m tonnes.
Ms Tan said that "although traders wary of the potential for a huge US 2012 crop, tight existing supplies and optimism about export demand are fuelling the rally".
On the bearish side, forecasts for snow in the northern plans are holding back prices a touch, in improving prospects for spring sowings there, which had looked threatened by dry weather.
Indeed, as US Commodities noted, "the planting season has begun", with 2% sown in Texas and other Gulf states set to begin imminently.
March corn added 0.1% in Chicago, to $6.54 ¼ a bushel, although the better-traded May lot eased 0.25 cents to $6.57 a bushel.
The new crop December lot gained 0.25 cents to $5.63 ¾ a bushel.
This was enough to gain a smidgen of ground against the November
The ratio of November soybeans: December corn stood at 2.29, down a touch from the 2.31 hit earlier in the week, if still showing a switch to the oilseed over this month, which started with a ratio of 2.11.
But even soybeans hardly looked out of favour with investors, with the March lot edging 0.1% higher to $13.07 a bushel, looking for an eighth successive day of gains.
The May lot was 0.1% higher at $13.13 ½ a bushel.
As Luke Mathews at Commonwealth Bank of Australia noted, "forecasts that world soybean production will fall by the largest annual amount ever in 2011-12, and further enquiry for US soybeans by the Chinese" are lending support to the oilseed.
However, soft commodities failed to join in the rises.
The May lot edged 0.4% lower to 25.24 cent a pound.
"The market expects sugar prices to initially correct lower following the March expiry," Ms Tan said.
"But there could be potential for the May premium over July to strengthen as a limited amount of sugar remained available for delivery against May, particularly with the timing of the Muslim holy month of Ramadan, which will boost demand. "
Expiry is coming up to being an issue for Chicago grains too, with Wednesday so-called first notice day, which begins the process.
Traders are expecting no deliveries against corn and not many, up to 300 contracts, against soybeans, and with potentially 500 deliveries against wheat futures.