Open-web future event prediction requires agents to distill reliable signals from noisy, redundant, and incomplete evidence. Existing retrieval/memory mechanisms directly feed retrieved information to agents or rely on simple memory functions such as storing and reusing prior information for prediction, leaving them insufficient for open-web forecasting. We propose to transform raw web evidence into structured memory before prediction, enabling agents to reason over distilled, question-specific evidence rather than noisy retrieval results. This paper presents ForeDreamer, a self-evolving dual-agent framework for managing memory over open-web evidence. ForeDreamer separates factual memory, a question-specific evidence state for the current forecast, from experiential memory, persistent agent experience accumulated across forecasting episodes. It uses a main agent for search and prediction, and a memory-processing subagent to convert search results into factual memory with dedicated tools. ForeDreamer further evolves experiential memory through two tracks, improving both forecasting decisions and factual-memory construction. Experiments on Prophet Arena and FutureX demonstrate the effectiveness of ForeDreamer. Project page: https://zhongzero.github.io/ForeDreamer
Figures & tables
Figure 1: Task mismatch of existing agent-memory systems. Traditional memory tasks often involve relatively clean, user-centered context and can be addressed by storing, retrieving, or reusing prior information. Open-web future event prediction instead requires agents to handle heterogeneous, noisy, and conflicting web data, which existing memory mechanisms are insufficient to process into forecast-ready evidence.
Figure 2: Overview of ForeDreamer. (a) During forecasting, the main agent uses forecasting experience from the Experience Bank, invokes a search-and-process tool to collect temporally valid evidence, and receives processed factual memory from a memory-processing subagent. The subagent follows a MemGuide and uses executable MemTools through an artifact workspace. (b) Rollout feedback drives dual-track self-evolution: textual forecasting experience evolves through validated edits to the Experience Bank, while procedural evidence-processing experience evolves through validated updates to the MemGuide tree and MemTools.
Figure 3: Evolution of procedural evidence-processing experience. (a) Vanilla rollout-based expansion grows a MemGuide tree by selecting a parent MemGuide, sampling an evolution rollout, deriving a design requirement, generating a candidate MemGuide and MemTools, and admitting the candidate through a validation gate. (b) Compositional tool reuse optimizes the candidate-generation step by selecting compatible existing MemTools before generating the MemGuide and any missing MemTools. (c) Diversity-guided exploration uses an evolution scheduler to retain the rollout-based path while adding an exploration path that generates category-diverse candidates from MemGuide-category summaries and representative MemGuides without requiring a new rollout result.
Figure 4: Hierarchical clustering of MemTools generated by vanilla procedural evolution on FutureX, using token-Jaccard source-code similarity. The reduced cluster count indicates that many generated MemTools share substantial token-level overlap, suggesting that vanilla evolution spends many attempts on near-duplicate operations.
Figure 5: Pipeline archetype distribution for vanilla rollout-based expansion on FutureX. All 10 evolved MemGuides fall into the same tool-orchestrated processing archetype, indicating limited exploration of alternative evidence-processing pipelines.
Model
Method
Climate/Weather
Companies
Economics
Entertainment
Mentions
Other
Politics
Sports
Avg. ( ↓ )
Qwen3.5-Flash
Full Text
0.3342
0.2657
0.0720
0.2005
0.2106
0.1306
0.2214
0.2122
0.2059
RAG
0.2511
0.2319
0.0752
0.1739
0.2178
0.1381
0.2094
0.2030
0.1876
HippoRAG 2
0.2798
0.2553
0.0524
0.1318
0.2020
0.1423
0.2069
0.1945
0.1831
Mem0
0.2792
0.2902
0.0695
0.1936
0.2308
0.1778
0.2423
0.2045
0.2110
MemoryOS
0.2385
0.2348
0.0542
0.1155
0.1917
0.1676
0.2216
0.1925
0.1771
A-MEM
0.2306
0.2591
0.0602
0.1516
0.2218
0.1542
0.2122
0.1996
0.1862
Table 1: Main comparison on Prophet Arena. The table reports Brier score for each category and the average score; lower values indicate better calibrated forecasts.
Model
Method
Accuracy ( ↑ )
Qwen3.5-Flash
Full Text
0.3298
RAG
0.3382
HippoRAG 2
0.3285
Mem0
0.3264
MemoryOS
0.3269
A-MEM
0.3495
Table 2: Main comparison on FutureX. The table reports prediction accuracy; higher values are better.
Method
Prophet Arena Avg. ( ↓ )
FutureX ( ↑ )
Full Text
0.2059
0.3298
w/o evolving MemGuide&MemTool
0.1663
0.3892
w/o evolving Experience Bank
0.1769
0.3351
ForeDreamer
0.1471
0.4108
Table 3: Dual-track experience ablation on Qwen3.5-Flash. Prophet Arena reports average Brier score, while FutureX reports accuracy.
Method
Prophet Arena Avg. ( ↓ )
FutureX ( ↑ )
Full Text
0.2059
0.3298
w/o Both Optimizations
0.1592
0.3850
w/o Compositional Tool Reuse
0.1541
0.4032
w/o Diversity-Guided Exploration
0.1554
0.3564
ForeDreamer
0.1471
0.4108
Table 4: Procedural-evolution optimization ablation on Qwen3.5-Flash. The variants remove Compositional Tool Reuse, Diversity-Guided Exploration, or both; Prophet Arena reports average Brier score, and FutureX reports accuracy.
Setting
Prophet Arena Full Text ( ↓ )
Prophet Arena ForeDreamer ( ↓ )
FutureX Full Text ( ↑ )
FutureX ForeDreamer ( ↑ )
Base Setting
0.2059
0.1471
0.3298
0.4108
Max Interaction Turns = 3
0.1871
0.1570
0.3894
0.4423
Max Interaction Turns = 4
0.1908
0.1629
0.3942
0.4279
Firecrawl Search
0.1995
0.1514
0.4394
0.4596
Top-2 Retrieved Results
0.1831
0.1514
0.3544
0.3606
Top-6 Retrieved Results
0.1845
0.1426
0.3398
0.4183
Table 5: Robustness across search settings on Qwen3.5-Flash. Each row changes one search or interaction configuration from the base setup and reports the corresponding comparison; Prophet Arena reports average Brier score, and FutureX reports accuracy.
Model
No Information
Full Text
ForeDreamer
Prophet Arena Avg. ( ↓ )
Qwen3.5-Flash
0.2545
0.2059
0.1471
GPT-5.4-Nano
0.2492
0.2084
0.1839
FutureX ( ↑ )
Qwen3.5-Flash
0.3077
0.3298
0.4108
GPT-5.4-Nano
0.2260
0.2766
0.3883
Table 6: Check for potential data leakage through no-information prompting. The table compares forecasting without web search against settings that use retrieved evidence.
Figure 6: MemTool similarity analysis on FutureX using token-Jaccard source-code similarity. Compositional Tool Reuse produces a less redundant tool set under the same clustering criterion.
Figure 7: MemGuide pipeline-archetype analysis on FutureX. Diversity-Guided Exploration encourages evolved guides to cover more pipeline archetypes, while vanilla rollout-based expansion remains concentrated in one archetype.
Appendix figures & tables14 assets
Supplementary material from the paper’s appendix.
Appendix
Model
Method
Climate/Weather
Companies
Economics
Entertainment
Mentions
Other
Politics
Sports
Avg. ( ↓ )
GPT-5-Nano
Full Text
0.1994
0.2870
0.1347
0.1989
0.2225
0.1897
0.2537
0.2066
0.2116
RAG
0.2438
0.2489
0.0988
0.1884
0.1997
0.1759
0.2658
0.2049
0.2033
HippoRAG 2
0.2250
0.2617
0.0987
0.2089
0.2437
0.1656
0.2607
0.2024
0.2083
Mem0
0.2124
0.3497
0.1373
0.2242
0.2024
0.2378
0.2751
0.2025
0.2302
MemoryOS
0.1366
0.2603
0.1354
0.2021
0.2412
0.2036
0.2598
0.2063
0.2057
A-MEM
0.2189
0.2786
0.1075
0.1935
0.2142
0.2021
0.2688
0.2032
0.2109
Appendix
Table S1: Additional Prophet Arena results for GPT-5-Nano. The table reports Brier score for each category and the average score; lower values indicate better calibrated forecasts.
Model
Method
Accuracy ( ↑ )
GPT-5-Nano
Full Text
0.3723
RAG
0.3942
HippoRAG 2
0.3894
Mem0
0.3776
MemoryOS
0.3667
A-MEM
0.3510
Appendix
Table S2: Additional FutureX results for GPT-5-Nano. The table reports prediction accuracy; higher values are better.
Method
Market Return ( ↑ )
Full Text
0.5790
RAG
0.5798
HippoRAG 2
0.6038
Mem0
0.4763
MemoryOS
0.4901
A-MEM
0.5679
Appendix
Table S3: Additional Prophet Arena average market-return results across categories on Qwen3.5-Flash; higher values are better.
Method
Climate/Weather
Companies
Economics
Entertainment
Mentions
Other
Politics
Sports
Avg. ( ↓ )
Full Text
0.3342
0.2657
0.0720
0.2005
0.2106
0.1306
0.2214
0.2122
0.2059
w/o evolving MemGuide&MemTool
0.2328
0.2199
0.0800
0.1125
0.1678
0.1274
0.1843
0.2056
0.1663
w/o evolving Experience Bank
0.2440
0.2492
0.0666
0.1351
0.1869
0.1306
0.2035
0.1996
0.1769
ForeDreamer
0.1770
0.2162
0.0414
0.0962
0.1573
0.1274
0.1742
0.1869
0.1471
Appendix
Table S4: Additional dual-track experience ablation on Prophet Arena for Qwen3.5-Flash. The table reports Brier score; lower values are better.
Method
Climate/Weather
Companies
Economics
Entertainment
Mentions
Other
Politics
Sports
Avg. ( ↓ )
Full Text
0.2275
0.3719
0.0631
0.1424
0.2878
0.1410
0.2257
0.2075
0.2084
w/o evolving MemGuide&MemTool
0.2275
0.3719
0.0963
0.1349
0.2878
0.1397
0.2222
0.2003
0.2101
w/o evolving Experience Bank
0.2251
0.3456
0.0547
0.1551
0.2915
0.1546
0.2230
0.2075
0.2071
ForeDreamer
0.1811
0.3456
0.0506
0.1117
0.2704
0.1272
0.1927
0.1919
0.1839
Appendix
Table S5: Additional dual-track experience ablation on Prophet Arena for GPT-5.4-Nano. The table reports Brier score; lower values are better.
Method
Accuracy ( ↑ )
Full Text
0.2766
w/o evolving MemGuide&MemTool
0.2766
w/o evolving Experience Bank
0.3404
ForeDreamer
0.3883
Appendix
Table S6: Additional dual-track experience ablation on FutureX for GPT-5.4-Nano. The table reports prediction accuracy; higher values are better.
Method
Climate/Weather
Companies
Economics
Entertainment
Mentions
Other
Politics
Sports
Avg. ( ↓ )
Full Text
0.3342
0.2657
0.0720
0.2005
0.2106
0.1306
0.2214
0.2122
0.2059
w/o Both Optimizations
0.2319
0.1948
0.0471
0.1096
0.1917
0.1169
0.1881
0.1935
0.1592
w/o Compositional Tool Reuse
0.1531
0.2149
0.0621
0.1038
0.1890
0.1226
0.1965
0.1907
0.1541
w/o Diversity-Guided Exploration
0.1747
0.1935
0.0602
0.1023
0.1823
0.1439
0.1921
0.1942
0.1554
ForeDreamer
0.1770
0.2162
0.0414
0.0962
0.1573
0.1274
0.1742
0.1869
0.1471
Appendix
Table S7: Additional procedural-evolution optimization ablation on Prophet Arena for Qwen3.5-Flash. The table reports Brier score; lower values are better.
Setting
Method
Climate/Weather
Companies
Economics
Entertainment
Mentions
Other
Politics
Sports
Avg. ( ↓ )
Base Setting
Full Text
0.3342
0.2657
0.0720
0.2005
0.2106
0.1306
0.2214
0.2122
0.2059
ForeDreamer
0.1770
0.2162
0.0414
0.0962
0.1573
0.1274
0.1742
0.1869
0.1471
Max Interaction Turns = 3
Full Text
0.2577
0.2437
0.0955
0.1354
0.2051
0.1639
0.2016
0.1941
0.1871
ForeDreamer
0.2165
0.2227
0.0655
0.0930
0.1741
0.1286
0.1710
0.1844
0.1570
Max Interaction Turns = 4
Full Text
0.2838
0.2196
0.1283
0.1830
0.1999
0.1408
0.1814
0.1897
0.1908
ForeDreamer
0.2480
0.2276
0.0538
0.0992
0.1672
0.1263
0.1974
0.1834
0.1629
Appendix
Table S8: Per-category results for additional search settings on Prophet Arena with Qwen3.5-Flash (Brier score; lower is better).
Method
Climate/Weather
Companies
Economics
Entertainment
Mentions
Other
Politics
Sports
Avg. ( ↓ )
No Information
0.2576
0.3837
0.1225
0.2634
0.2576
0.2390
0.2945
0.2177
0.2545
Full Text
0.3342
0.2657
0.0720
0.2005
0.2106
0.1306
0.2214
0.2122
0.2059
ForeDreamer
0.1770
0.2162
0.0414
0.0962
0.1573
0.1274
0.1742
0.1869
0.1471
Appendix
Table S9: Per-category data-leakage check on Prophet Arena for Qwen3.5-Flash. The table reports Brier score; lower values are better.
Method
Climate/Weather
Companies
Economics
Entertainment
Mentions
Other
Politics
Sports
Avg. ( ↓ )
No Information
0.2043
0.4272
0.1441
0.1973
0.2911
0.2310
0.2774
0.2210
0.2492
Full Text
0.2275
0.3719
0.0631
0.1424
0.2878
0.1410
0.2257
0.2075
0.2084
ForeDreamer
0.1811
0.3456
0.0506
0.1117
0.2704
0.1272
0.1927
0.1919
0.1839
Appendix
Table S10: Per-category data-leakage check on Prophet Arena for GPT-5.4-Nano. The table reports Brier score; lower values are better.
Dataset
Similarity metric
τ
w/o tool reuse
w/ tool reuse
Δ
FutureX
AST sequence
0.4
54.73%
68.18%
+13.46%
FutureX
AST sequence
0.5
67.66%
79.55%
+11.88%
FutureX
AST sequence
0.6
83.58%
84.09%
+0.51%
FutureX
Normalized sequence
0.4
23.88%
36.36%
+12.48%
FutureX
Normalized sequence
0.5
41.79%
45.45%
+3.66%
FutureX
Normalized sequence
0.6
57.21%
63.64%
+6.42%
Appendix
Table S11: Effect of compositional tool reuse on MemTool similarity clusters. Values are cluster ratios after converting to percentages; higher ratios indicate that fewer tools are merged into similarity clusters and therefore suggest less redundant tool generation. Δ is computed as w/ tool reuse minus w/o tool reuse.
Figure S1: Hierarchical clustering of vanilla FutureX MemTools using normalized token-sequence similarity. The result shows substantial sequence-level overlap among generated tools, complementing the token-Jaccard analysis in the main text.
Figure S2: Hierarchical clustering of vanilla FutureX MemTools using AST node-sequence similarity. Even when lexical details are abstracted away, non-singleton clusters remain, indicating repeated structural patterns in generated tools.
Figure S3: Detailed pipeline-archetype analysis for FutureX MemGuides. Without diversity-guided exploration, all 10 MemGuides fall into Tool-Orchestrated Processing. With diversity-guided exploration, the guides cover four archetype patterns, showing broader procedural exploration.
Agentic forecasting is important for decision-making in dynamic environments, but it remains challenging because agents must reason from incomplete, time-limited evidence and produce calibrated probabilities before outcomes are resolved. Memory provides a natural mechanism for transferring experience from resolved forecasts to future prediction tasks. However, existing agent-memory methods are not tailored to forecasting, as they typically store past interactions, reflections, or factual associations without explicitly representing reusable predictive factors or calibration knowledge. We propose ForecastCompass (FoCo), an adaptive factor-based memory framework for agentic forecasting. FoCo organizes forecasting experience with a hierarchical forecasting-task taxonomy, enabling retrieval task-relevant forecasting knowledge. It maintains two complementary memory components: factor memory, which captures reusable predictive dimensions, and reasoning memory, which encodes probability updating, uncertainty handling, and calibration principles. Using retrospective analyses as learning signals, FoCo iteratively revises memory through a verbalized memory-revision procedure, enabling the agent to accumulate transferable forecasting knowledge over time. Experiments on Prophet Arena and FutureX with GPT-5-mini and Gemini-2.5-Flash show that FoCo improves both probabilistic accuracy and calibration.
Forecasting future events is a critical challenge for large language model (LLM) agents, spanning domains from elections and monetary policy to financial markets. However, evaluating progress on this task presents a fundamental trade-off between efficiency and environment fidelity. While live evaluation benchmarks suffer from an inherently slow feedback loop, existing retrospective replays typically restrict agents to static, pre-frozen databases that sacrifice the environmental realism of actual deployments. To tackle this issue, we introduce Agentic Time Machine (TM), an infrastructure that approximately reconstructs the web state at any chosen past time by filtering post-cutoff content. Leveraging this evaluation infrastructure, we further propose a planner-solver-aggregator multi-agent framework that breaks each question into diverse analytical angles, gathers evidence in parallel, and combines the results into a single forecast. Experiments show that offline scores under TM correlate strongly with live FutureX scores, validating that TM offers a fast and reliable sandbox for forecasting-agent evaluation. On FutureX-Past and Polymarket evaluated under TM, our framework achieves the highest score among strong closed-book, tool-augmented, and self-consistency baselines. On the official FutureX live leaderboard, our system achieves the best average rank over four consecutive weeks, including 1st place in May Week 1. As of June 17, it also ranks 1st on FutureX's official eight-week overall leaderboard.
Forecasting requires large language model (LLM) agents to gather evolving evidence, revise their beliefs, and make calibrated predictions over time. Yet evaluating and improving these capabilities is challenging because real-world events unfold continuously and outcomes may take months to resolve. We introduce Forecast-Dojo, a replayable environment that reconstructs resolved prediction-market events as sequences of dated forecasting steps, enabling reproducible evaluation, longitudinal analysis, and training from agent interactions. It comprises 1,568 Polymarket events split temporally into training and evaluation sets, alongside 18.8 million dated news articles. Across 12 models, research tools consistently improve forecasting performance, and greater capture of new evidence is associated with larger improvements over time. Nevertheless, all models trail historical market forecasts, while carrying a belief notebook across dates reduces research costs without consistently improving forecast quality. We supervise fine-tuned Qwen3-30B-A3B-Thinking-2507 on collected trajectories from Qwen3-235B-A22B-Thinking-2507 to demonstrate the environment's training utility. The student's accuracy is improved from 34.8% to 42.8% on the evaluation set.
Liqin Ye, Haorui Wang, Fardin Ahmed +8
Georgia Institute of Technology · Amazon · University of Florida