Reading Port & Chokepoint Signals

Understanding Maritime Data for Trade Prediction

Prediction markets on global trade require interpreting real-world signals before they become official statistics. Ports and chokepoints generate continuous data streams—vessel movements, queue lengths, transit times—that forecast throughput, congestion, and trade flows weeks before monthly reports publish.

This module teaches you how to read maritime signals, distinguish noise from actionable patterns, and translate physical observations into trading opportunities.

Core Port Signals

1. Anchorage Queue (Waiting Vessels)

Definition: Number of vessels anchored offshore waiting for berth assignment.

Why It Matters: Anchorage queues are leading indicators of port activity. Ships arrive 1-5 days before berthing, so queue growth predicts increased throughput (assuming vessels eventually berth and unload cargo).

How to Read It:

Normal Queue: 5-15 vessels for major container ports (LA, Singapore, Shanghai) Elevated Queue: 20-40 vessels indicates strong demand or operational bottlenecks Crisis Queue: 50+ vessels signals severe congestion (October 2021 LA/Long Beach had 70+ vessels)

Example:

You're trading a binary market: "Will Port of Los Angeles exceed 900,000 TEUs in December 2024?"

Signal Check (Dec 5, 2024):

• Current anchorage queue: 28 vessels (up from 12 vessels on Nov 5)
• Historical December average: 15 vessels
• Interpretation: Queue doubled in 30 days and is 87% above normal—strong signal for high throughput

Data Source: IMF PortWatch (free), MarineTraffic (paid for detailed analytics)

2. Container Dwell Time

Definition: Average days a container remains at the terminal after unloading before trucked/railed away.

Why It Matters: Dwell time measures operational efficiency and demand-side pickup capacity. Rising dwell indicates congestion (containers piling up); falling dwell suggests smooth operations or weak demand.

Benchmarks:

• Optimal: 2-3 days (container unloaded, customs cleared, trucker picks up quickly)
• Normal: 3-5 days (typical for busy ports)
• Congested: 5-7 days (chassis shortages, trucker delays, rail bottlenecks)
• Crisis: 7+ days (operational breakdown, storage overload)

Example:

You're analyzing Port of Houston for a scalar market (TEU range forecast).

Signal Check:

• Current dwell time: 6.2 days (up from 3.8 days two months ago)
• Interpretation: Congestion building—containers arriving faster than they're leaving. This CAPS throughput growth (can't unload new ships if terminal is full). Forecast: Throughput growth slows or turns negative.

Data Source: Port authority monthly reports (some ports publish weekly)

3. Berth Utilization Rate

Definition: Percentage of time berths are occupied by vessels (100% = every berth always has a ship).

Why It Matters: Utilization over 85% indicates capacity constraints—port is near maximum throughput. Utilization under 60% suggests excess capacity or weak demand.

How to Interpret:

• 60-75%: Healthy (room to grow, no bottlenecks)
• 75-85%: High utilization (port is busy, slight delays possible)
• 85-95%: Near capacity (queue times increase, throughput growth limited)
• 95%+: Maxed out (physical constraint—can't handle more volume)

Example:

Port of Singapore berth utilization: 88% (up from 72% six months ago)

Implication: Singapore approaching capacity limits. If demand continues rising, throughput will flatten (physically can't berth more ships). This is a signal to sell high-range buckets in scalar markets betting on further growth.

4. Vessel Arrival Counts (Leading Indicator)

Definition: Number of container ships arriving per week/month (tracked via AIS satellite data).

Why It Matters: Arrivals precede unloading by 3-7 days. If arrivals surge, throughput follows (assuming normal unloading times).

How to Use:

Track rolling 30-day arrival counts. Compare to same period last year.

Example:

Port of Charleston — December 1-15, 2024:

• Container ship arrivals: 45 vessels (up from 38 vessels Dec 1-15, 2023)
• Average capacity per vessel: 8,000 TEUs
• Implied cargo: 45 × 8,000 = 360,000 TEUs (vs 304,000 last year = +18%)

Forecast: December throughput likely +15-20% year-over-year (allowing for some empty slots on vessels).

Data Source: AIS platforms (MarineTraffic, VesselFinder) or IMF PortWatch aggregated statistics

Core Chokepoint Signals

1. Daily/Monthly Transit Counts

Definition: Number of vessels passing through a chokepoint (Suez Canal, Panama Canal, Malacca Strait, etc.) per day or month.

Why It Matters: Chokepoints are pipelines connecting trade routes. Declining transits signal rerouting (Cape of Good Hope instead of Suez) or reduced trade volumes. Rising transits indicate normalization or demand growth.

Benchmarks (monthly):

• Suez Canal: 1,800-2,000 vessels (normal), fewer than 1,600 (crisis/rerouting)
• Panama Canal: 1,000-1,100 vessels (normal), fewer than 900 (drought restrictions)
• Malacca Strait: 6,500-7,000 vessels (normal, highly stable)

Example:

You're trading Suez Canal transit volume for January 2025.

Signal Check (Dec 20, 2024):

• December (to-date) transits: 1,150 vessels (on pace for ~1,500 monthly)
• Historical January average: 1,850 vessels
• Red Sea security: Houthi attacks ongoing, shipping lines avoiding Red Sea

Interpretation: December running 19% below normal; if security doesn't improve, January will remain suppressed. Forecast: 1,500-1,600 transits (below 1,800 threshold in binary market).

2. Queue at Chokepoint Entry

Definition: Vessels waiting to enter a chokepoint (common at Panama due to draft/scheduling restrictions).

Why It Matters: Queues indicate capacity bottlenecks. Panama Canal's queue spiked to 200+ vessels in 2023 due to drought (reduced daily transit slots). Long queues mean delayed transits and potential rerouting.

Example:

Panama Canal queue (Gatun Lake low water):

• Current queue: 35 vessels (waiting 4-8 days for transit slot)
• Normal queue: fewer than 10 vessels (1-2 day wait)

Implication: Daily transit capacity cut from 36 ships to 28 ships. Monthly transits will fall. If queue persists, shippers will route around Africa or via Suez—forecast: Panama transits down 15-20%.

3. Transit Time (Days to Cross)

Definition: Average time for a vessel to complete chokepoint transit.

Normal Benchmarks:

• Suez Canal: 12-16 hours (northbound or southbound)
• Panama Canal: 8-10 hours (full transit, Pacific to Atlantic)
• Malacca Strait: 20-24 hours (depends on route through strait)

Delays Signal Congestion or Operational Issues:

If Suez transit time jumps to 24-36 hours, it indicates convoy delays, pilot shortages, or berth congestion at Port Said.

Combining Port and Chokepoint Signals

Scenario: You're forecasting Port of Los Angeles December 2024 throughput.

Step 1: Check Chokepoint Inputs

• Panama Canal transits (Dec 1-20): Down 12% YoY → less Asia→East Coast cargo rerouting to LA (neutral to slight negative for LA)
• Suez Canal transits: Down 18% YoY → more Asia→Europe cargo going around Cape (no impact on LA)

Verdict: Chokepoint signals are neutral for LA (Trans-Pacific route unaffected).

Step 2: Check Port Direct Signals

• Anchorage queue: 28 vessels (up from 15 normal) → +87% = strong demand signal
• Dwell time: 4.1 days (normal range) → no congestion bottleneck
• Berth utilization: 82% (high but not maxed) → capacity available
• Vessel arrivals (Dec 1-15): 52 ships vs 47 last year → +11% YoY

Step 3: Synthesize Forecast

• Queue surge (+87%) + arrival growth (+11%) + no operational bottlenecks = high confidence in strong throughput
• Forecast: 920,000-950,000 TEUs (vs 880,000 last December = +5-8%)

Step 4: Trade Setup

Binary Market: "Will LA exceed 900,000 TEUs in December?" (YES at $0.62)

Your Analysis: 85% probability YES (queue and arrivals both strong)

Trade: Buy YES at $0.62 (expected value: 0.85 × $1 - $0.62 = +$0.23 per share, 37% expected return)

Where to Find Maritime Data

Free Sources

1. IMF PortWatch (https://portwatch.imf.org/): Port throughput, chokepoint transits, anchorage data, updated weekly
2. Port Authority Websites: Monthly TEU reports (search "[port name] monthly statistics")
3. Suez Canal Authority: Monthly transit reports
4. Panama Canal Authority: Daily/weekly transit and queue data
5. MarineTraffic (limited free tier): Live vessel positions, basic port activity

Paid/Advanced Sources

1. MarineTraffic Pro: Historical AIS data, port call analytics, dwell time
2. S&P Global Panjiva: Trade data, supply chain analytics
3. Clarksons Research: Freight rates, vessel utilization, capacity analysis
4. Lloyd's List Intelligence: Port rankings, congestion indices

Common Mistakes

Mistake 1: Ignoring Seasonality

Problem: Comparing October throughput to November throughput without accounting for seasonal peaks.

Solution: Always compare to same month last year (Dec 2024 vs Dec 2023), not prior month (Dec vs Nov).

Mistake 2: Overreacting to Single-Day Signals

Problem: Seeing 2-day queue spike and assuming long-term congestion.

Solution: Track rolling 7-day or 30-day averages. One-day anomalies (weather delays, single large vessel) are noise.

Mistake 3: Ignoring Lag Between Signal and Outcome

Problem: Vessels arrive on Dec 1-15 but official TEU report covers Dec 1-31. Your signal only captures half the month.

Solution: If forecasting monthly outcome, ensure signal window matches (track full month of arrivals before predicting monthly throughput).

Practical Exercise

Task: Forecast Port of Oakland January 2025 throughput using public data.

Step 1: Visit IMF PortWatch, check Oakland anchorage queue and recent monthly TEU trends.

Step 2: Visit Port of Oakland website, find December 2024 TEU report (published mid-January).

Step 3: Compare December 2024 to December 2023 (YoY growth rate).

Step 4: Check anchorage queue as of January 1-10. Is it higher or lower than December average?

Step 5: Synthesize: If December was strong (+10% YoY) AND January queue is elevated, forecast continued strength (predict January +8-12% YoY).

Step 6: Check Ballast Markets for Oakland January market. If market implies +5% and your forecast is +10%, buy the high-range bucket.

Ready to Apply What You've Learned?

Turn knowledge into action.

Start Trading on Ballast Markets →

Use real-world port and chokepoint signals to inform your prediction market trades. Apply the analysis techniques from this module to identify mispriced contracts.

Next Steps

Continue Learning:

• Prediction Markets 101 — Understand binary, scalar, and index market mechanics
• Position Sizing & Liquidity — Manage risk when trading on port signals
• Binary vs Scalar Markets — Choose the right market type for your signal

Practice on Real Ports:

• Port of Los Angeles — Track the largest U.S. container port
• Port of Singapore — World's busiest transshipment hub
• Suez Canal — Critical Europe-Asia chokepoint

Disclaimer

This content is for educational purposes only and does not constitute financial advice. Maritime data can be delayed, incomplete, or subject to revisions. Prediction markets involve risk. Always verify data sources and use multiple signals before trading.

Disclaimer

This content is for informational purposes only and does not constitute investment advice, financial advice, trading advice, or recommendations. Market conditions can change rapidly. Always conduct your own research and consult with qualified professionals before making trading decisions.