That seasonal bounce in soybeans, which was meant to kick off last Thursday, is struggling a bit.

The idea is that soybeans stage a bit of a bounce at this time of year, as pressure from harvest supplies eases, with October 4 proving historically the day to buy.

While this year October 4 did produce a bounce, this week has not been so kind to prices, especially in the last session, when Chicago's spot November contract gave up decent gains to close a little lower.

This time the lot did not even bother with the early gains, although its declines were limited, by 0.1% to $15.48 ½ a bushel as of 09:20 UK time (03:20 Chicago time).

Crunch point?

Are more volatile times looming?

Technical analysis suggests they could be. Futures have for most of the last three weeks stuck to a patch of turf between their 10-day and 100-day moving averages.

But that area is shrinking as the two lines converge, with the 10-day now at some $15.54 a bushel, and 100-day at $15.41 a bushel.

That potentially means that something more eventful is in the mix as futures decide to continue trading underneath their 10-day moving average, or stick above the 100-day which they have not finished beneath for four months.

"Yes, something will happen one way or the other very soon," Mike Mawdsley at broker Market 1 said.

'Stellar demand'

A likely trigger point is Thursday's US Department of Agriculture Wasde crop report, which will settle (for now) the argument over just how big the US harvest of the oilseed is with yield ideas improving, albeit from a low base, as harvest results have come in.

Still, export and domestic consumption has proved stronger than expected too, with the US already having orders for more than 80% of expected exports in 2012-13, a little over a month into the season.

"News has been bullish for soybeans, demand stellar," Mike Mawdsley at Market 1 said.

"But how much crop to we have? We will learn more very soon."

'Pipelines not getting enough grain'

Bulls might like to think they had the advantage, given that investors have already factored in quite some upgrade to the US soybean yield in Thursday's Wasde report, of more than 3 bushels per acre from the current 35.4 bushels per acre, potentially lining up the market for a fall.

And indeed, analysts have a habit of overestimating soybean, and corn, yields ahead of October Wasde briefing.

"It would take a bean yield 39 bushels per acre or higher to be bearish as market has kicked around a possible 40 bushels per acre or higher since early October," Richard Feltes at RJ O'Brien said.

"We think it will take some surprisingly large bushels per acre on Thursday to turn row crop markets lower simply because, as basis and spreads suggest, corn and soy pipelines are not getting enough grain."

Funds to cut positions?

Whether corn, which is pinned beneath its 10-day and 20-day moving averages, is prepared for a break-out, well, investors were betting too heavily on that either in early deals.

The last session was "another fairly quiet one in the market and much of the same is expected for Wednesday", Brian Henry at Benson Quinn Commodities said.

However, ahead of the Wasde "funds may look to reduce long exposure which could weigh on the market", although it had not in early deals, when the December lot was 0.1% higher at $7.42 ¾ a bushel.

USDA data overnight showed the US corn harvest a little slower than the market had expected last week, hitting 69% completion instead of the figure of at least 70% investors had forecast, although that is not too much of a worry given that the pace is still historically fast.

'Behind schedule'

Corn also got help from wheat, which remained the bull's favourite in Chicago, helped by the USDA report overnight showing that while US winter wheat sowings were only marginally behind the usual pace, emergence of seedlings was further behind.

"Emergence rates remain behind schedule at 23%, down from the five-year average of 30%," Luke Mathews, at Commonwealth bank of Australia, said.

At RJ O'Brien, Richard Feltes flagged "renewed concern over Australian production prospects", where dryness remains a threat to maturing grains as harvest approaches (and has in some areas started).

Wheat for December added 0.6% to $8.69 ½ a bushel.

Chart convergence

In New York, cotton, for which the Wasde is also a key event, was little changed, edging 0.1% higher to 71.92 cents a pound for December delivery.

The lot also appears technically to be approaching something of a chart crunch point, standing below its 100-day moving average at 72.36 cents a pound, but above its 10-day, at 71.65 cents a pound.

Raw sugar for March added 0.1% to 21.48 cents a pound, facing downward pressure from revived Indian expectations for exports in 2012-13, but support from Tuesday's poor Brazil Centre South data, showing the smallest fortnightly production since June.