Crops were mixed on what analysts said may be a key day for deciding the next trend in prices, and whether the reversal in the last session was more than a flash in the pan.
Are the funds that have driven prices higher of late beginning to hold back?
"If [Wednesday's] reversal holds, it appears to signal a short to mid-term change in price movement and the grain markets could easily pull back 5-15 cents in corn and 20-30 in beans by week's end," Justin Kelly at US broker eHedger said.
"Prices are trading near/through some key resistance levels, so technical traders will place a lot of emphasis on closing prices the remainder of the week."
Rival broker Benson Quinn Commodities said that bearish investors were "convinced that once the speculative money dries up, the bearish fundamentals are quick to kick in and set the market back."
Indeed, Wednesday's close, for soybeans, "near the low end of the daily trading range may be a signal for additional profit taking with the market closing higher five out of the last eight trading sessions".
While soybeans did show some sign of nerves in early deals, dipping to $10.22 a bushel for January delivery, the contract had recovered to $10.31 a bushel by 7:40 GMT, up 4 cents on the day.
December corn was also a touch higher, adding 1.25 cents to $3.99 ¼ a bushel, attempting to close back above the hard-won $4 a bushel mark.
There was some talk of fundamentals playing a role here, with Meteorlogix forecasting enough rain to cause "disruptions" to delayed corn and soybean harvests in southern and eastern parts of the US Midwest.
Wheat, however, raised hopes for the bears, declining 4.5 cents to $5.61 ¾ a bushel for December delivery.
One factor which may play a role later in the day is the result of Egypt's latest wheat tender, although the relatively high price of US wheat has dimmed hopes of it scoring highly, if at all.
As for palm oil, Kuala Lumpur investors decided enough was enough for now on a rally which has driven it to three-month highs.
The threat is still there of the heavy rain which looks set to put October's sharp production increase in Malaysia into reverse. The country, the second ranked palm oil producer, has kept a warning alert for heavy rains in the central state of Pahang.
The questions are where, whether and in what quantities the rain spreads, and whether for example it hits the top palm oil producing state of Johor to the south.
The rain is expected to reduce yields, besides disrupting the harvesting process.
The benchmark February contract stood 6 ringgit lower at 2,394 ringgit a tonne.