For most markets, it was reduced fears of something snapping that fostered gains.

That something being investors' patience with Spain, which was boosted by Moody's decision to maintain the country at an investment-grade credit rating, albeit with negative outlook.

London's FTSE 100 share index added 0.7% to return above 5,900, around the top of its range of recent months, with shares in Madrid itself soaring 2.4%.

The safe haven of the dollar dropped 0.5%, boosting the appeal of dollar denominated assets such as many commodities.

Indeed, the CRB commodities index gained 0.5%, despite a drop of $1 a barrel or so in Brent crude back below $113 a barrel.

Micronaire nightmare

However, there was one asset which did especially well because of heightened concerns of snapping.

That asset was cotton, which soared the daily limit of 3.0 cents a pound, or 4.0%, in New York for December delivery - the contract's highest close in five months.

The problem is the poor quality of the crop, which has fostered a rally in cotton despite what appeared a downright bearish picture last Thursday, when the US Department of Agriculture upgraded its estimate for world stocks to a (yet higher) record high.

High levels of so-called "micronaire", coarse fibres which carry a higher risk of breaking during processing, in the US crop have raised questions about just how real these huge inventories are – in America, the top exporter, at least.

'Unlikely to prove lasting'

"The percent of cotton that can be delivered... is much lower than I have seen in many years," Sharon Johnson, at Georgia-based broker Knight Futures said, citing the high levels of coarse fibre as "behind the quality issue".

Commerzbank analysts, saying "there appear to be problems at present with short-term availability and quality" of US cotton, flagged the slightly tardy pace of the American harvest, 28% completed as of Sunday, compared with 30% typically by now.

With only 46% of that crop hitting the quality needed for delivery against New York futures, stocks certified by the Big Apple's Ice exchange have dropped to 7,800 bales, down from 18,500 bales a year ago.

That said, Commerzbank was, given the weak global fundamentals, not optimistic about the rally having stamina, saying that "ewe regard the tightening of supply as merely temporary, so the price increase it has triggered is unlikely to prove lasting".

Quality factor in grains too

Cotton's jump stole some of the thunder from what was a better day in Chicago, where the main crops this time managed to hang on to early headway.

Investors are taking stock of whether the significant losses in corn, soybeans and wheat from summer highs have not left values below levels needed to ration thin supplies.

"The market is now at support and trying to base," US Commodities said.

Prices are being helped in this process by the winding down of the US harvest, reducing the pressure from a seasonal jump in supplies.

Harvest pressure has this year, after all, been exacerbated by the poor quality of the soybean and, in particular, corn crops, which has made many farmers reluctant to risk storing it.

"There are definitely producers that would normally store corn and soybeans at home that have opted to sell the lower-quality grain in fear of quality loss in their bins," Darrell Holaday at Country Futures said.

Ethanol boost

However, with harvest pressure passing, now "the cash market will help dictate the direction of the market, the cash market will be the guide", US Commodities said.

And that is more positive for futures. "Basis levels are on the rise," the broker said, with RJ O'Brien's Richard Feltes also flagging the "firm cash market".

OK, as far as exports go, US corn is still being undercut by foreign supplies, with USDA corn export sales data on Thursday expected to come in at 100,000-300,000 tonnes, low by historic standards (if representing a huge rise from the 14,200 tonnes the week before).

But ethanol production eased only slightly last week, to 797,000 barrels a day, with inventories down too, by some 300,000 barrels to 19m barrels.

"Production is still on a yearly pace that would be 3% above the current USDA projection for the crop year," Country Futures' Darrell Holaday said.

"Most anticipation is that production in the current week, as reported next week, will be higher as margins have improved slightly."

'Lack of rain in Brazil'

He also flagged "some buying in the soybean complex caused by the lack of rain in northern Brazil.

"The southern regions have received good moisture and the models point to reasonable moisture, but the northern areas are dry and need some rain in the next couple of weeks."

US Commodities flagged too that, in soybeans, "US crush margins are strong as soymeal demand remains brisk", while Brazil is reported not to be offering cargos for February, which buyers are desperate for, to refill the pipeline sapped by weak South American and US crops.

Soybeans for November closed up 1.0% at $15.09 ¼ a bushel.

Chicago December corn rose in line to $7.45 ½ a bushel.

'Gotten more competitive'

Wheat for December achieved a 1.0% gain too, to $8.56 ¼ a bushel, helped by specific factors besides the improved sentiment abroad in ag markets.

Benson Quinn Commodities flagged the "the prospects for US wheat export business into North Africa continue to improve".

Even though Algeria at a tender this week bought 400,000 tonnes of wheat likely from South America, and potentially France, the good news for US exporters is that "little by little the European Union pipeline is being absorbed," bringing on the time when importers will need to turn to the US instead.

"US offers have gotten more competitive outside of the freight spread."

Australia setbacks

And Australia is looking less and less likely to prove such a strong competitor in export markets, with wheat from its main producing state, Western Australia, becoming temporarily the world's most expensive as harvest hopes took another knock.

Meanwhile, in Europe, customs data showed the UK, following its dire harvest (it is still raining) entrenching its position as a net wheat importer, in contrast with its typical position.

London wheat for November added 1.0% to £198.50 a tonne, while Paris wheat for November eased 0.4% to E256.50 a tonne, depressed by a firmer euro.