· Analytic
Z4411 USDA AMS Rail Index (Grain Transportation)
The USDA AMS Grain Transportation Report rail index z-score , captures spot rail-tariff rates for US grain shipments from interior terminals. Elevated rail rates signal active export flow drawing grain from country elevators toward port terminals, historically bullish for corn forward returns.
Current reading
+0.746
Extreme Pos
DAILY · SIGNAL
As of Oct 30, 2026. Updated nightly.
Current composite
+0.6828
On the plus-or-minus one scale; rail rates significantly above 2-year rolling mean
Signal state
Extreme POS
52 consecutive days in episode
All-time percentile
87.6th
Upper-decile of 36 years
extreme-pos corn fwd 60d
+4.07%
1,372 days (15.3%), HAC t +3.90 sig at 1%
extreme-neg corn fwd 60d
-2.02%
1,057 days (11.8%), HAC t -2.70 sig at 1%
Corn Transport Composite (C-TRD-4) contribution
33%
One of 3 member Zs in Corn Transport Composite (C-TRD-4) Corn Directional Allocator
OBJECTIVE
The USDA Agricultural Marketing Service Grain Transportation Report publishes a weekly rail index tracking spot tariff rates on US grain shipments from the interior terminal network (BNSF + Union Pacific + Canadian National railway lines serving the Corn Belt). The rail index is one of five freight-mode cost components in the GTR (alongside diesel, river barge, ocean-Gulf, ocean-PNW), but rail-specific dynamics carry particular corn-market information: approximately 25 percent of US corn exports move by rail to Pacific Northwest ports for Asian destination buyers (China + Japan + Korea + Taiwan + Southeast Asia). When rail rates rise, it signals active rail-car demand drawing grain from the Corn Belt toward PNW export terminals , a direct corn-export-flow signal. This signal queries the AMS GTR weekly rail_index column, forward-fills daily, z-scores on a 504-day rolling window with 60-day minimum, and tanh-bounds. The empirical pattern across 36 years is cleanly monotonic trend-following. extreme-pos state (val above plus 0.5, rail rates significantly above 2-year rolling norm) delivers mean corn fwd 60d of plus 4.07 percent (HAC Newey-West t plus 3.90, significant at the 1 percent level, 1,372 state-days). extreme-neg state (val below minus 0.5, rail rates significantly below) delivers minus 2.02 percent (HAC t minus 2.70, significant at 1 percent, 1,057 state-days). Both extreme tails HAC-t significant with directionally-expected signs. The signal reads +0.746 as of October 23 2026 in extreme-pos territory for 52 consecutive trading days at the 87.6 percentile of 36 years. The reading reflects elevated 2025-2026 rail freight demand consistent with the strong US corn export program. The signal contributes 33 percent weight to Corn Transport Composite (C-TRD-4) Corn Directional Allocator (one of 3 member Zs) with polarity sign plus one.
LIVE CHART
Thirty-six years of USDA AMS GTR rail index z-score.
COMPOSITE
0.7 / 100
STATE
Extreme Pos
PHASE
+1
FWD 60d
+3.23% (baseline +2.31%)
SAMPLE N
9,039 days
TODAY’S PLAYBOOK READING
STATE
Extreme Pos
STATE AND PERCENTILE
extreme-pos at the 87.6 percentile , upper-decile of 36 years.
WHY THE SIGNAL IS HERE
Active 2025-2026 US corn export program drawing grain from Corn Belt toward PNW + Gulf export terminals, elevating rail-car demand and tariff rates.
POSTURE FOR THE WEEKS AHEAD
extreme-pos has historically delivered plus 4.07 percent corn fwd 60d , bullish empirical pattern.
WHAT THE CHART SHOWS
The composite sits at +0.75 in the Rail Rates Elevated band (deep extreme). The blue signal line has been in the elevated band as US corn export flow pulls grain through interior terminals. The full-sample Spearman IC vs CBOT corn fwd 60d is +0.161 at p=1.9e-25 (deeply significant positive). CBOT front-month corn (orange, right axis) sits near $4.48/bu.
TOP INPUTS FIRING
- Primary composite +0.75 State Rail Rates Elevated, 92nd percentile. US rail-tariff rates for grain shipments running meaningfully above baseline.
- USDA AMS Grain Transportation Report rail index Spot rail-tariff rates for US grain shipments from interior terminals (country elevators) toward port and processing destinations. Elevated rates indicate active export demand pulling grain through the system.
- IC vs CBOT corn fwd 60d: Spearman +0.161, p=1.9e-25 (N=4,133) Strongly significant positive IC: elevated rail rates predict positive corn fwd 60d. The demand-flow mechanism is firing in the author-thesis direction.
THE TAKEAWAY
What this means for you today
THE RAIL EXPORT-FLOW CHANNEL
US corn exports move via two primary modes to overseas destinations: approximately 60 percent via river barge to the Gulf export complex (New Orleans), approximately 25 percent via rail to the Pacific Northwest export terminals (Portland + Longview + Tacoma + Seattle serving Asian buyers), and the balance via truck + rail to Mexican destinations. The rail index specifically captures BNSF + UP + CN tariff rates on grain shipments. Rising rail rates signal active rail-car demand drawing grain from the Corn Belt toward PNW terminals , a direct corn-export-flow signal.
THE CLEAN MONOTONIC EMPIRICAL PATTERN
Both extreme tails are HAC-t significant at the 1 percent level with directionally-expected signs. extreme-pos (high rail rates = active export flow) delivers plus 4.07 percent corn fwd 60d; extreme-neg (low rail rates = soft export flow) delivers minus 2.02 percent. The signal is one of three Corn Transport Composite (C-TRD-4) Corn Directional Allocator member Zs along with USDA AMS River Barge Index (river barge index) and Grain Transport Cost Composite (5-component composite). The three signals collectively read the complete grain-transport-cost regime.
THE HONEST CAVEAT
The signal is correlated with Grain Transport Cost Composite (which includes rail_index as one of 5 components) and complementary to USDA AMS River Barge Index River Barge Index (same AMS GTR table, different column). All three are in the Corn Transport Composite (C-TRD-4) Corn Directional Allocator. The AMS GTR weekly data has approximately 7-day publication lag not explicitly applied in the engine , a mild residual look-ahead. The rail index reads BNSF + UP + CN tariff rates but does not capture spot-market rail-car bidding or auction dynamics directly.
THE REGIME MAP
The three USDA AMS Rail Index regime states, forward returns and sample share
Behavior across the USDA AMS Grain Transportation Report rail-index z-score signal (CBOT corn benchmark). The signal reads spot rail-tariff rates for US grain shipments from interior terminals: elevated rates signal active export flow drawing grain to ports; soft rates signal demand slack. Author-thesis-aligned bullish on positive composite.
| State | Phase | Share | Fwd 60d | HAC t | Edge vs baseline | Last firings |
|---|---|---|---|---|---|---|
| Rail Rates Soft | – | 16.1% (1453 d) | +1.41% | +1.12pp | Feb 2026, Apr 2025, Nov 2024 | |
| Rail Rates Neutral | 0 | 65.3% (5903 d) | +1.52% | +1.23pp | Jun 2026, Feb 2026, Jan 2026 | |
| Rail Rates Elevated TODAY | + | 18.7% (1688 d) | +4.30% | +4.01pp | Aug 2026, Apr 2026, Dec 2025 |
The historical pattern
Methodology
THE TRACK RECORD
State changes
| State | Start | End | Duration | Fwd 60d SPY |
|---|---|---|---|---|
| Extreme Neg | 10/23/2024 | 11/12/2024 | 15d | +4.92% |
| Extreme Pos | 11/13/2024 | 02/11/2025 | 61d | +1.03% |
| Normal | 02/12/2025 | 02/18/2025 | 4d | -6.47% |
| Extreme Neg | 02/19/2025 | 03/25/2025 | 25d | -3.67% |
| Normal | 03/26/2025 | 04/08/2025 | 10d | +5.55% |
| Extreme Pos | 04/09/2025 | 09/23/2025 | 115d | +13.07% |
| Normal | 09/24/2025 | 10/07/2025 | 10d | +1.99% |
| Extreme Neg | 10/08/2025 | 11/18/2025 | 30d | +2.17% |
| Normal | 11/19/2025 | 12/09/2025 | 14d | +3.57% |
| Extreme Neg | 12/10/2025 | 12/16/2025 | 5d | -1.51% |
| Normal | 12/17/2025 | 12/23/2025 | 5d | -0.09% |
| Extreme Neg | 12/24/2025 | 01/06/2026 | 8d | -5.39% |
| Normal | 01/07/2026 | 02/10/2026 | 24d | -4.44% |
| Extreme Pos | 02/11/2026 | 02/24/2026 | 9d | +6.60% |
| Normal | 02/25/2026 | 03/31/2026 | 25d | +7.15% |
| Extreme Neg | 04/01/2026 | 06/23/2026 | 57d | +13.09% |
| Normal | 06/24/2026 | 08/18/2026 | 39d | +3.88% |
| Extreme Neg | 08/19/2026 | 10/23/2026 | 47d |
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 `fundamentals_data.USDA_AMS_GTR_TRANSPORT_COSTS_WEEKLY.rail_index` weekly. Forward-fills daily. Z-scores on 504-day rolling window with 60-day minimum. Tanh-bounds. Five-state machine on the final RL_Feature_Value.
GO DEEPER
Want the full depth?
The full research brief adds methodology detail on the USDA AMS Grain Transportation Report release cadence, which rail corridors drive the index, and how spot rail-tariff rates differ from secondary transportation signals (barge, truck, ocean). Includes four historical case studies anchored to actual rail-rate extremes, the three-regime state-conditional table, and the methodology for pairing with the Ending Stocks, CFTC positioning signals, 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 11:56 AM ET