· Analytic
Z4491 FAS PSD Ukraine Corn Stocks
The USDA Foreign Agricultural Service Production Supply and Distribution series for Ukraine corn ending stocks, market-year YoY change, polarity-inverted and z-scored on a 1,260-day rolling window. High Ukraine ending stocks mean more export competition in the Black Sea corridor, which historically drags on CBOT corn forward returns. Low Ukraine stocks (war disruption, drought, logistics collapse) tighten global exportable supply and historically support CBOT corn forward returns.
Current reading
-0.494
Moderate Neg
DAILY · SIGNAL
As of Oct 30, 2026. Updated nightly.
Current composite
-0.494
On the plus-or-minus one scale; Ukraine stocks reading on the LOW side of baseline
Signal state
Moderate NEG
Sustained Ukraine stocks LOW regime
Phase
STRESS
Stress-aligned read; low-Ukraine-stocks regime
60-day IC (daily)
-0.141
p=1.3e-37 across 8,228 live rows (non-overlap caveat below)
Avg edge NEG band
+1.64pp
Mean fwd 60d +1.99% vs +0.35% baseline across 2,519 state-days
Avg edge POS band
-1.42pp
Mean fwd 60d -1.08% vs +0.35% baseline across 3,372 state-days
OBJECTIVE
The USDA Foreign Agricultural Service Production Supply and Distribution database tracks national balance sheets for every major grain-producing country. Ukraine was the number-four corn exporter in the world before the February 2022 invasion and remains a critical Black Sea corridor supplier even through the war years. This signal reads Ukraine corn ending stocks by marketing year, computes the year-over-year percent change against the prior marketing year, polarity-inverts the series (low Ukraine stocks map to a positive signal reading), interpolates to daily, z-scores on a 1,260-day rolling window, and tanh-bounds to the plus-or-minus one range. The polarity inversion reflects the economic read: low Ukraine stocks tighten exportable supply globally, which supports CBOT corn forward returns. High Ukraine stocks mean a well-supplied Black Sea corridor and more export competition for US origin, which drags on CBOT corn forward returns. The 36-year empirical pattern across 8,228 live trading days is clean and monotone. Composite below minus 0.5 (Ukraine stocks LOW band, 30.4 percent of sample) delivers mean corn fwd 60d of plus 1.99 percent, an edge of plus 1.64 pp above the plus 0.35 percent unconditional baseline. Composite above plus 0.5 (Ukraine stocks HIGH band, 40.7 percent of sample) delivers mean corn fwd 60d of minus 1.08 percent, an edge of minus 1.42 pp. The directional spread is approximately 3.1 pp. Daily Spearman IC against CBOT Corn fwd 60-day return is minus 0.1406 at p-value 1.3e-37 across 8,228 observations. Today the signal reads minus 0.4936 as of October 30, 2026, in Ukraine stocks LOW band territory and in a sustained MODERATE_NEG state. The historical pattern for the LOW band is supportive for US corn forward returns. Read on for the mechanism, the signature historical cases, and the current reading in context.
LIVE CHART
Thirty-six years of USDA FAS PSD Ukraine corn ending-stocks YoY dynamics.
The signal reads composite minus 0.4936 as of October 30, 2026, in sustained MODERATE_NEG state and against the edge of the Ukraine stocks LOW band. The latest USDA FAS Ukraine corn ending-stocks reading is on the LOW side of the 1,260-day rolling baseline, consistent with multi-year war-disruption revisions since the February 2022 invasion. Per the global-exportable-supply channel, this is supportive for US corn forward returns. CBOT front-month corn (orange, right axis) sits near $4.48/bu.
COMPOSITE
-0.5 / 100
STATE
Moderate Neg
PHASE
-1
FWD 60d
+1.99% (baseline +0.35%)
SAMPLE N
8,228 days
TODAY’S PLAYBOOK READING
STATE
Moderate Neg
STATE AND BAND
MODERATE_NEG state with composite minus 0.4936, sitting at the edge of the Ukraine stocks LOW band (composite below minus 0.5). Reading reflects a tight-Ukraine-stocks posture after multi-year war disruption to Black Sea corridor supply.
WHY THE SIGNAL IS HERE
Ukraine ending-stocks revisions have moved progressively lower across the war years since February 2022. The inverted-z-scored series fires on the LOW side of baseline through this period.
POSTURE FOR THE WEEKS AHEAD
The Ukraine stocks LOW band historically delivers plus 1.99 percent corn fwd 60d (edge plus 1.64 pp above baseline). The read is supportive for US corn on the global-exportable-supply-tightening channel.
WHAT THE CHART SHOWS
The composite sits at -0.49 on the Ukraine stocks LOW side of baseline. The USDA FAS Ukraine corn ending-stocks YoY series, inverted and z-scored, is reading tight after multi-year war-disruption revisions since the February 2022 invasion. Per the global-exportable-supply channel, this is supportive for US corn forward returns. CBOT front-month corn (orange, right axis) sits near $4.48/bu.
TOP INPUTS FIRING
- Primary composite -0.49 State MODERATE_NEG, on the edge of the Ukraine stocks LOW band. Inverted-z-scored FAS PSD Ukraine ending-stocks series reads tight after multi-year war-disruption revisions.
- USDA FAS PSD Ukraine, Aug-1 marketing-year anchor Marketing-year ending stocks for Ukraine corn (country code UP), YoY percent change, polarity-inverted, z-scored on 1,260-day rolling window with 60-day minimum.
- Daily Spearman IC vs CBOT corn fwd 60d: -0.141 at p=1.3e-37 Deeply significant headline statistic. Non-overlapping-period reading at minus 0.092 and p-value 0.28 (N=138) is not standalone significant. Autocorrelation inflation disclosed. Regime-conditional edges in the three bands are the economically meaningful output.
THE TAKEAWAY
What this means for you today
THE GLOBAL SUPPLY SIDE READS LOW
Ukraine corn ending stocks are reading on the LOW side of the inverted-z-scored series as of October 30, 2026. Composite minus 0.4936 places the signal in the MODERATE_NEG state and against the edge of the Ukraine stocks LOW band. The empirical interpretation of this regime is that global exportable corn supply tightens as the number-four pre-war exporter runs lean. The historical pattern is clean and monotone across 36 years. Ukraine stocks LOW (composite below minus 0.5, 30.4 percent of sample) delivers mean CBOT corn fwd 60d of plus 1.99 percent, an edge of plus 1.64 pp above the plus 0.35 percent unconditional baseline. Ukraine stocks HIGH (composite above plus 0.5, 40.7 percent) delivers minus 1.08 percent, an edge of minus 1.42 pp. The spread between the two bands is approximately 3.1 percentage points.
THE WAR-DISRUPTION CHANNEL IS LIVE
The February 2022 Russian invasion of Ukraine, the subsequent July 2022 Black Sea Grain Initiative, and the July 2023 initiative lapse are all visible episodes in the series. Across the war years USDA FAS has progressively revised Ukraine ending stocks lower as Black Sea corridor logistics, planting disruptions, and demand destruction compound. The current reading reflects this cumulative downward revision pattern. The practical read for a corn trader is that the global exportable supply channel is running tight on the Black Sea side, and US origin picks up more of the global demand flow than it would in a well-supplied Ukraine year.
NON-OVERLAPPING-PERIOD CAVEAT
The headline daily Spearman IC of minus 0.1406 at p-value 1.3e-37 across 8,228 live rows is inflated by serial correlation. Sampling the series on non-overlapping 60-day blocks produces a reading of minus 0.0917 at p-value 0.2849 across N=138 blocks, not significant at the five-percent level. Read this as a regime-tilt indicator rather than a standalone directional alpha. The regime-conditional edges in the three bands are the economically meaningful output, not the headline daily statistic.
THE REGIME MAP
The three Ukraine corn-stocks regime states, forward returns and sample share
Behavior across the USDA FAS PSD Ukraine corn ending-stocks YoY series, polarity-inverted and z-scored on a 1,260-day rolling window. INVERSE polarity: high Ukraine stocks mean more Black Sea export competition and are bearish for CBOT corn forward returns; low Ukraine stocks tighten global exportable supply and are supportive.
| State | Phase | Share | Fwd 60d | HAC t | Edge vs baseline | Last firings |
|---|---|---|---|---|---|---|
| Ukraine stocks low TODAY | – | 30.4% (2519 d) | +1.99% | +1.64pp | Mar 2025, Aug 2020, Dec 2018 | |
| Ukraine stocks normal | 0 | 28.9% (2397 d) | +0.66% | +0.31pp | Sep 2024, Mar 2022, Aug 2020 | |
| Ukraine stocks high | + | 40.7% (3372 d) | -1.08% | -1.42pp | May 2022, Mar 2020, Sep 2016 |
The historical pattern
Methodology
THE TRACK RECORD
State changes
| State | Start | End | Duration | Fwd 60d SPY |
|---|---|---|---|---|
| Ukraine stocks normal | 10/30/2024 | 03/12/2025 | 91d | +3.76% |
| Ukraine stocks low | 03/13/2025 | 10/30/2026 | 412d | +8.75% |
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_FAS_PSD from `fundamentals_data.USDA_FAS_PSD` for `commodity=’Corn’`, `country_code=’UP’` (Ukraine), `attribute=’Ending Stocks’`. Marketing year anchor is August 1 of the starting calendar year. Computes year-over-year percent change, interpolates monthly values to daily via a month-end-aware function, z-scores on a 1,260-day rolling window with 60-day minimum, polarity-inverts so that LOW stocks map to a POSITIVE signal, and tanh-bounds to plus-or-minus one. Five-state machine on the final primary composite.
GO DEEPER
Want the full depth?
The full research brief adds methodology detail on the USDA FAS PSD source, the Ukraine marketing-year anchoring, and the global-exportable-supply mechanism that connects Ukraine stocks to CBOT corn forward returns. Includes historical case studies anchored to the February 2022 invasion, the July 2023 Black Sea Grain Initiative lapse, the 2014 Crimea era, and the 2016 record-crop counter-case. Covers the three-regime state-conditional table and the methodology for pairing with the US stocks sibling, the US-vs-global price-ratio signal, the China export-sales signal, and the Corn Cycle DNA playbook.
Taxonomy, polarity, state labels
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 03:56 PM ET