NAPERVILLE, Illinois, Sept 24 (Reuters) - Speculators have held bullish views toward Chicago soybeans for the last three-and-a-half years, though the optimism has soured this month as an enormous Brazilian bean crop has been satisfying global needs since early this year.

That has allowed CBOT soy futures to decline over the last few weeks because despite a shrinking U.S. harvest, export demand for U.S. beans has been unusually poor so far this month.

Most-active November soybeans dropped more than 2% in the week ended Sept. 19, and money managers reduced their net long in CBOT soy futures and options to 45,832 contracts from 73,815 a week earlier. The new stance is funds’ least bullish in three months.

That move was primarily the result of exiting longs, which is backed by market data. Trading volume for CBOT soybeans in the week ended Sept. 19 was notably above normal for the week, and open interest in bean futures and options surged 5% on the week.

Soybean open interest as of Sept. 19 was at a three-year high for the week and a 15-month high outright, having risen 19% in the latest six weeks. That compares with an 8% jump in the same period a year ago.

CBOT November beans fell 1.5% in the last three sessions, hitting a six-week low on Friday of $12.92-1/2 per bushel. Strong trade volume continued at least both Wednesday and Thursday, a possible signal that investors have shed additional bean length.

In the week ended Sept. 19, money managers increased their net long in CBOT soybean oil futures and options by nearly 6,200 to 47,064 contracts, though they cut their net long in soymeal futures and options by about 6,300 to 55,873 contracts.

That was associated with a 2.2% fall in most-active soymeal futures and a fractional rise in soyoil. On Friday, soyoil hit a six-week low of 58.26 cents per pound, losing 1% in the last three sessions.

Soymeal hit a one-month low on Friday of $385.10 per short ton, falling about 1% between Wednesday and Friday. However, traders are watching for displaced Argentine soymeal export business to get rerouted to the United States, which has seen a bump in export sales in recent weeks.

GRAINS

Through Sept. 19, money managers increased their net short in CBOT wheat futures and options to a three-month high of 96,805 contracts from 84,139 a week earlier. That is funds’ most bearish wheat view for the date since 2016, when open interest was about 15% higher.

However, CBOT wheat open interest has risen recently and trading volume was above average during the latest week, similar to the trend in soybeans. Wheat open interest was up 14% in the three weeks ended Sept. 19, and futures slipped nearly 3% in that time frame.

Most-active CBOT wheat fell fractionally in both the week ended Sept. 19 and the following three sessions. Global wheat prices continue to be pressured by ample Black Sea supplies, and the U.S. dollar hit a six-month high on Friday, which can soften export demand for U.S. grains.

Money managers through Sept. 19 were net sellers of Minneapolis wheat futures and options for an eighth consecutive week, expanding their net short to a three-year high of 15,177 contracts. Futures were largely unchanged during that week, but spring wheat has traded near contract lows this month.

Most-active CBOT corn was steady in the week ended Sept. 19, though money managers extended their net short in corn futures and options to a three-year high of 144,815 contracts versus 134,909 in the prior week. New shorts explained most of the move.

Corn on Sept. 19 dropped to $4.67-3/4 per bushel, the most-active contract’s lowest level since December 2020, though futures drifted fractionally higher in the last three sessions.

Corn trading volumes were mixed over the last several sessions, though open interest in futures and options remains at 10-year lows for the date. Corn open interest has not made anomalous strides in the latest few weeks as have been observed in beans and wheat. Karen Braun is a market analyst for Reuters. Views expressed above are her own.

(Reporting by Karen Braun Editing by Matthew Lewis)