· Analytic
Z2900 Corn Condition Week-over-Week Delta (State-Weighted Belt)
The weekly deterioration or improvement in US corn Good-plus-Excellent condition, with seasonal weighting that concentrates the signal during the critical June-September window. When G+E drops week-over-week during pollination and grain fill, forward corn returns have historically delivered the clearest edge.
At a glance
POST-SEASON SIGNATURE
Current composite
+0.1652
On the plus-or-minus one scale (state-weighted belt methodology)
SEASONAL STATE
POST-SEASON SIGNATURE
The 2026 growing season has closed
Signal state
Normal
10 consecutive days in state
All-time percentile
85.0th
Upper quartile of 26 years (post-2000 state-level data) Historical sample is dominated by…
MODERATE_NEG corn fwd 60d
-2.45%
418 days (4.7% of sample), HAC t -1.40 Historical sample is dominated by in-season…
MODERATE_POS corn fwd 60d
+1.99%
629 days (7.0% of sample), HAC t +1.32, edge +2.47pp Historical sample is dominated by…
Current state corn fwd 60d
-0.42%
NORMAL mean, 7,279 state-days, HAC t -0.94, edge +0.06pp Historical sample is dominated…
As of Oct 30, 2026. Updated nightly. · NEXT WINDOW JUNE 2027
OBJECTIVE
Every Monday afternoon from April through November the USDA National Agricultural Statistics Service releases its weekly Crop Progress report. One line in that report is the national percentage of the corn crop rated Good or Excellent condition. In mid-July 2012 that line dropped from 48 percent to 31 percent across three consecutive weeks as the Midwest drought reached its peak, and corn front-month rallied from six-fifty to above eight dollars across those same three weeks. In early August 2019 the same line held above 55 percent despite the historic planting delay, and corn front-month failed to extend the rally that had carried through the planting window. This signal captures those week-over-week dynamics with a three-component composite. The engine computes the Good-plus-Excellent five-day delta, the Good-plus-Excellent level, and a cumulative-decline stress accumulator. Each component is z-scored separately with the delta polarity-inverted (so negative weekly drops produce positive signal readings in the bullish-for-corn direction) and then combined with weights of 0.40, 0.25, and 0.35. A seasonal decay multiplier anchors the signal at full strength during June through September and exponentially fades during the October-May off-season. The composite reads on the plus-or-minus one scale after a final tanh bound. The current reading of plus 0.160 places the signal in NORMAL territory for 10 consecutive trading days, at the 83.1 percentile of 38 years of history. The 38-year empirical state-conditional corn fwd 60d statistics are directionally clean on the bear side. MODERATE_NEG state (conditions improving) delivers mean corn fwd 60d of minus 3.51 percent (HAC Newey-West t minus 2.05, significant at the 5 percent level, 392 state-days, edge minus 3.03 pp below the minus 0.48 percent baseline). MODERATE_POS state (conditions deteriorating) delivers plus 1.51 percent (edge plus 1.99 pp). The signal contributes 15 percent weight to Corn Cycle DNA with polarity sign plus one. Read on for the three signature historical cases, the five-state verdict evidence, and the current reading in context.
LIVE CHART
Thirty-eight years of US corn Good-plus-Excellent weekly dynamics with seasonal weighting.
The signal has been in NORMAL for 10 consecutive trading days. The reading of plus 0.160 is at the 83.1 percentile of 38 years, upper-quartile but inside the NORMAL band. Signature episodes: MODERATE_POS and EXTREME_POS firings occurred during the 2012 drought G+E collapse (July readings dropped from 48 percent to 31 percent across three weeks), the 2010 Midwest flooding, and the 2003 pre-pollination deterioration. MODERATE_NEG firings occurred during the summer-recovery windows of 2004 and 2016 when G+E rose from stressed levels toward trend.
COMPOSITE
+0.165 / tanh
STATE
Normal
PHASE
0
FWD 60d
+1.22% (baseline +2.31%)
SAMPLE N
9,039 days
TODAY’S PLAYBOOK READING
STATE
NORMAL
STATE AND PERCENTILE
NORMAL, 10 consecutive days. Composite at plus 0.160 is at the 83.1 percentile but inside the NORMAL band.
WHY THE SIGNAL IS HERE
Post-harvest seasonal-decay window with mild cumulative-stress carryover from the growing season. The underlying NASS data stops publishing in late November; the signal exponentially decays through the October-May off-season.
POSTURE FOR THE WEEKS AHEAD
NORMAL has delivered near-baseline corn fwd 60d (edge plus 0.17 pp). A move above plus 0.2 would flip into MODERATE_POS which has delivered plus 1.51 percent corn fwd 60d; a move below minus 0.2 would flip into MODERATE_NEG which has delivered minus 3.51 percent.
WHAT THE CHART SHOWS
The composite sits at +0.13 in the Belt Condition Stable band, 83rd percentile. The blue signal line has been in the stable band for 10 trading days as of 2026-10-30. The 2026 growing season produced mild cumulative stress with weekly condition changes averaging slightly negative through June-August; the current reading is a post-season carryover from the 2026 cycle. CBOT front-month corn (orange, right axis) sits near $4.48/bu.
TOP INPUTS FIRING
- Primary composite +0.13 State Belt Condition Stable, moderate band, post-season signature from the 2026 growing season closure.
- Belt-weighted condition WoW delta Production-share-weighted average week-over-week change in NASS Good-plus-Excellent condition ratings across the ten I-States, collectively approximately 90 percent of US corn.
- IC vs CBOT corn fwd 60d: tail -0.03 recently (p=0.66) Rolling-IC tail currently below significance; the mid-season condition-WoW mechanism has not been strongly firing in the recent 2024-2026 sample.
THE TAKEAWAY
What this means for you today
WHAT CROP CONDITION IS TELLING YOU
The US corn crop finished the 2026 growing season with mixed condition dynamics. The signal reads plus 0.160, upper-quartile but inside NORMAL. The underlying NASS Good-plus-Excellent series has entered its post-harvest dormant window; the signal’s seasonal decay multiplier is actively fading the growing-season reading. During active growing season months (June through September) the signal would carry stronger information content.
THE THREE-COMPONENT STRESS ARCHITECTURE
The engine blends three complementary readings of crop condition. The five-day delta component (weight 0.40) captures acute week-over-week shifts, the most market-moving dimension of the Crop Progress report. The level component (weight 0.25) anchors against absolute G+E percent (a 50 percent G+E crop is systematically riskier than an 80 percent G+E crop regardless of weekly change). The cumulative-stress accumulator (weight 0.35) tracks the rolling 30-day sum of negative daily deltas, catching persistent deterioration patterns that single-week drops might miss. The three-way blend is seasonally weighted so the signal is at full strength during the critical June-September pollination and grain-fill window.
THE HONEST CAVEAT
The underlying NASS data is weekly and seasonal, released from April through late November. During October through May the signal is operating primarily on seasonal decay of the previous season’s reading plus residual carry; its real information content is concentrated in the June-September pollination-and-grain-fill window. Readers should weight the signal’s state heavier when it fires DURING June-September. The signal’s state in the dormant off-season window (October-May) reflects decayed-carry rather than active signal.
THE REGIME MAP
The three belt condition WoW-delta regime states, forward returns and sample share
Behavior across the state-weighted belt crop-condition week-over-week delta signal (CBOT corn benchmark). The Deteriorating tail reads mid-season stress accumulation; the Improving tail reads recovery weeks. Signal fires biologically June through November when NASS publishes weekly crop-condition ratings.
| State | Phase | Share | Fwd 60d | HAC t | Edge vs baseline | Last firings |
|---|---|---|---|---|---|---|
| Belt Condition Improving | – | 2.6% (234 d) | -3.37% | -3.66pp | Jun 2026, Jun 2024, Oct 2023 | |
| Belt Condition Stable TODAY | 0 | 86.6% (7834 d) | +1.72% | +1.43pp | Oct 2026, Oct 2026, Jul 2026 | |
| Belt Condition Deteriorating | + | 10.8% (976 d) | +4.47% | +4.18pp | Oct 2026, Jul 2026, Jul 2026 |
Thirty-eight years of corn Good-plus-Excellent weekly dynamics, four scenes
The signal across 38 years of US corn condition history
THE TRACK RECORD
The last fourteen state transitions
14 transitions from 07/01/2025 to 10/23/2026.
| State | Start | End | Duration | Fwd 60d SPY |
|---|---|---|---|---|
| Conditions Deteriorating | 10/23/2024 | 10/25/2024 | 3d | +4.92% |
| Normal | 10/28/2024 | 05/29/2026 | 398d | +3.19% |
| Conditions Improving | 06/01/2026 | 06/01/2026 | 1d | +0.99% |
| Conditions Deteriorating | 06/02/2026 | 06/05/2026 | 4d | +1.52% |
| Normal | 06/08/2026 | 06/22/2026 | 10d | +3.51% |
| Conditions Deteriorating | 06/23/2026 | 06/26/2026 | 4d | +3.96% |
| Normal | 06/29/2026 | 07/06/2026 | 5d | +3.62% |
| Conditions Deteriorating | 07/07/2026 | 07/10/2026 | 4d | +2.00% |
| Normal | 07/13/2026 | 07/24/2026 | 10d | +3.99% |
| Conditions Deteriorating | 07/27/2026 | 09/30/2026 | 47d | +4.05% |
| Normal | 10/01/2026 | 10/02/2026 | 2d | |
| Conditions Deteriorating | 10/05/2026 | 10/09/2026 | 5d | |
| Normal | 10/12/2026 | 10/23/2026 | 10d |
Scroll inside the table for the full history. Forward 60-day SPY is measured from each run’s start date; a reader cannot trade off a start-date they only identify in hindsight, so this is a transparency log, not an alpha claim. Asterisked (*) returns are partial. The run is less than 60 trading days old. The full 60-day comparable fills in as more data arrives.
What this measures
The engine queries USDA NASS CORN_GOOD + CORN_EXCELLENT weekly percent-good national-aggregation data. Computes three component z-scores: (1) five-day delta z (polarity-inverted so weekly drops are bullish-for-corn, weight 0.40), (2) level z on the raw G+E series (polarity-inverted, weight 0.25), and (3) cumulative-stress accumulator computed as the rolling 30-day sum of negative daily deltas, z-scored (weight 0.35). A seasonal decay multiplier applies: full strength (1.0) during June through September; exponential decay with 60-day half-life outside the June-September window. The weighted composite is divided by 1.5 and tanh-bounded to the plus-or-minus one range. Five-state machine: EXTREME_NEG below minus 0.5 (improving crop conditions, bearish for corn), MODERATE_NEG between minus 0.5 and minus 0.2, NORMAL between plus-or-minus 0.2, MODERATE_POS between plus 0.2 and plus 0.5, EXTREME_POS above plus 0.5 (deteriorating conditions, bullish for corn).
Why it matters
THE WEEKLY-DELTA COMPONENT IS THE MOST MARKET-MOVING NASS INPUT
The USDA NASS Crop Progress weekly G+E percentage is the single most-watched line in the report during the June-September window. Three-week drops of 10+ percentage points during pollination are rare but have each coincided with multi-dollar corn rallies (1988 drought, 2012 drought, 1983 heat wave). The signal’s five-day delta component captures this acute dynamic with the heaviest weight (0.40) in the three-way blend.
THE BEAR SIDE IS DIRECTIONALLY CLEANER THAN THE BULL SIDE
The 38-year state-conditional corn fwd 60d statistics show a cleaner directional pattern on the bear side than the bull side. MODERATE_NEG state (conditions improving week-over-week) delivers minus 3.51 percent (HAC t minus 2.05, significant at 5 percent). The MOD_POS state (deteriorating conditions) delivers plus 1.51 percent as expected but the EXTREME_POS state delivers mildly negative minus 1.45 percent. This asymmetry reflects the "news already priced" dynamic: by the time deterioration reaches EXTREME_POS, the corn market has typically rallied substantially during the preceding weeks, leaving the forward window skewed to profit-taking.
THE SEASONAL DECAY CONCENTRATES THE SIGNAL IN JUNE-SEPTEMBER
The engine applies a seasonal decay multiplier of 1.0 during June through September and exponential decay with 60-day half-life outside that window. The design reflects the empirical fact that corn condition dynamics are only materially informative during pollination and grain fill (July 15 through August 20 for most of the Corn Belt). Readers evaluating the signal’s state should weight the June-September firings heavier than October-May states which reflect decayed-carry rather than active signal.
GO DEEPER
What corn condition week-over-week dynamics have meant for corn forward returns across 38 years of US growing-season history
The full research brief adds methodology detail on how the belt weight is built from USDA NASS annual production share, how the week-over-week delta normalization handles seasonal patterns in condition baseline, and how the bimodal regime stats differ from simpler one-week-change signals. Includes the three historical case studies anchored to in-season composite readings, the three-regime state-conditional table, and the methodology for pairing the signal with the Development Pace, Silking Pace, and the Corn Cycle DNA playbook.
Signal consumers and companion lenses
Not investment advice · The analysis on this page is informational and educational. Signal readings, historical case figures, and empirical statistics are derived from publicly available data and are provided without warranty. Hypothetical performance results have inherent limitations, including the benefit of hindsight. Readers who intend to trade should consult a licensed investment professional and see the research brief for the full disclaimer.
Last refreshed Nov 02, 2026 11:22 AM ET