NAPERVILLE, Illinois, June 30 (Reuters) - Speculators deepened their short bets in Chicago traded corn ahead of last week’s major U.S. data release, establishing their most bearish-ever corn views for the end of June.

In the week ended June 25, money managers boosted their net short in CBOT corn futures and options to 277,666 contracts, an increase of more than 86,000 on the week. That marked funds’ biggest weekly net selling in corn since May 2023 and was the result of both new shorts and exiting longs.

December corn futures shed more than 5% in the four-session week ended June 25, which was the year’s biggest four-session slide until Friday. Modest U.S. demand and favorable weather forecasts encouraged the negative sentiment.

Money managers had held a very similar corn position on the same date in 2020, but they quickly covered shorts as the U.S. Department of Agriculture’s June survey showed drastically fewer planted corn acres than anticipated for the 2020 harvest.

Friday featured the opposite scenario, as USDA estimated 2024 U.S. corn plantings at 91.475 million acres, above the range of trade guesses and 1.6% higher than in the March survey. This is the fourth time in six years that USDA’s June corn area fell outside the analyst range.

Funds’ corn selloff in the days before the report paid off as December corn fell another 5% in the last three sessions, stamping a new yearly low of $4.12 per bushel on Friday.

U.S. soybean plantings came in below the average trade guess for a 10th consecutive year, though the 86.1 million acres were within the expectation range. November soybeans surged briefly on Friday’s data, but inked a new yearly low of $11.00 per bushel just before the close.

November beans lost 0.7% between Wednesday and Friday, following a 1.8% decline in the week ended June 25.

Money managers that week continued their steepest selloff in CBOT soybean futures and options since December 2019, extending their net short to an eight-week high of 129,663 contracts from 105,970 a week prior. New gross shorts accounted for most of the move.

That also sets up funds’ most bearish end-of-June position in soybeans, topping 2017’s high of nearly 119,000 contracts.

CBOT September wheat plunged more than 6% in the week ended June 25, bringing four-week losses to 22%. That put futures close to the contract low of $5.50 per bushel, though wheat popped more than 2% in the last three sessions with strength on Thursday.

In the week ended June 25, money managers lifted their net short in CBOT wheat futures and options to a nine-week high of 70,487 contracts from 52,732 in the prior week. That included more than 21,000 new gross shorts, the most for any week since December 2017.

The new wheat stance is funds’ second most bearish for the date after 2016, and the net short is larger than the year-ago position for the first time in three months.

U.S. markets will be closed on Thursday, though traders will continue to monitor weather forecasts for U.S. corn and soybeans, which enter sensitive development periods in July. As of Sunday, the short-term weather outlook appeared largely non-threatening to crops. Karen Braun is a market analyst for Reuters. Views expressed above are her own.