E2A-Bench: Benchmarking Evidence-to-Action Reliability in Financial Chart Reasoning
Organizations: Tsinghua University · Jinan University
Abstract
Can financial vision-language models (VLMs) turn chart evidence into reliable action recommendations? Existing hallucination evaluations are mostly claim-centric; they assess whether generated statements are supported, but not whether evidence remains traceable through rationale, confidence, and final action. We introduce E2A-Bench, a 969-query benchmark for financial chart reasoning, constructed from 323 HS300 constituents under three input modalities with deterministic OHLCV-derived evidence anchors. E2A-Bench evaluates grounding, reasoning-action consistency, evidence-confidence calibration, and directional coverage through UCR, RCI, ECI, and NDR, where NDR measures coverage-aware evidence-to-action reliability rather than realized trading performance. Evaluating 20 VLMs reveals three failures hidden by scalar hallucination scores: the lowest-UCR model ranks near the bottom by NDR due to only 6.4% directional coverage; oracle-aided verification reduces unsupported claims but can collapse coverage; and financial fine-tuning amplifies the BUY:SELL ratio by factors of 4.21 to 4.68 across strict base-fine-tuned pairs. These results show that financial VLM evaluation should trace the full evidence-to-action chain rather than rely on a single hallucination score. Code and data: https://github.com/wanng-ide/E2A-Bench
Figures & tables
| Benchmark | Scale | #Inp. | Main evaluation target | Ev. | Act. | Cov. |
| CharXiv | 2K charts | 1 | Realistic chart QA | ✗ | ✗ | ✗ |
| ChartHal | 2K claims | 1 | Hallucination detection | ✓ | ✗ | ✗ |
| VisFinEval | 1K Q&A | 1 | Financial chart QA | ✗ | ✗ | ✗ |
| FinChart-Bench | 5K Q&A | 1 | Financial chart QA | ✗ | ✗ | ✗ |
| E2A-Bench (ours) | 1K Q&A | 3 | Evidence-to-action reliability | ✓ | ✓ | ✓ |
| Fact Key | Compact Definition |
|---|---|
| MA alignment | Ordering of MA5, MA10, and MA20 on the last day |
| MA cross | Golden/death cross of MA5 and MA10 in the last 5 days |
| Volume change | Current volume relative to the 20-day mean |
| Price breakout | Current close relative to the preceding 20-trading-day high–low band, excluding the evaluation day |
| Trend direction | Linear-regression slope of 20-day close prices |
| Volatility | Annualized volatility of recent returns |
| Statistic | Value |
|---|---|
| Stocks | HS300 constituents |
| Input modalities | text-only, chart-only, multimodal |
| Benchmark queries | |
| Evidence anchors | total facts |
| Input token length, mean std. | text-only: ; chart-only: ; multimodal: |
| Model | Size | Cov. | |||||
|---|---|---|---|---|---|---|---|
| Proprietary | |||||||
| Gemini-3.1-Pro | – | 59.0 | 70.0 | 67.5 | 5.2 | 7.5 | 16.8 |
| Gemini-3.1-Flash | – | 37.9 | 58.1 | 53.8 | 2.7 | 6.3 | 16.0 |
| Claude-Sonnet-4.6 | – | 55.1 | 71.5 | 69.4 | 3.6 | 1.9 | 16.0 |
| GPT-5.5 | – | 25.9 | 61.2 | 47.6 | 2.0 | 4.0 | 12.8 |
| GPT-5.4 | – | 15.2 | 65.4 | 54.4 | 2.7 | 4.1 | 6.5 |
Appendix figures & tables12 assets
Supplementary material from the paper’s appendix.
Appendix
| Signal Type | Qualifying Labels |
|---|---|
| Price breakout | breakout_high , breakout_low |
| Volume anomaly | heavy_volume , light_volume |
| Strong trend | uptrend or downtrend with /day |
| Vol–price divergence | bullish_divergence , bearish_divergence |
| Extreme price position | high_zone , low_zone |
| Momentum acceleration | accelerating_up , accelerating_down |
| Quantity | Value |
|---|---|
| Stocks | |
| Input modalities | |
| Benchmark queries | |
| Evaluated models | |
| Recorded response cells | |
| Max claim judgments / response |
| # | Fact Key | Dimension | Inputs | Computation Rule | Output Labels | ECI Signal |
|---|---|---|---|---|---|---|
| 1 | MA alignment | MA stacking | Close | Compare MA5, MA10, and MA20 on the last day. | bullish , bearish , mixed | No |
| 2 | MA cross | Short-term crossover | Close | Detect golden/death cross of MA5 and MA10 within the last 5 days. | golden_cross , death_cross , no_cross | Yes |
| 3 | Volume change | Volume anomaly | Volume | Compare current volume with the 20-day mean; heavy if , light if . | heavy_volume , light_volume , normal_volume | Yes |
| 4 | Price breakout | Range breakout | Close, High, Low | Compare the evaluation-day close with the high and low over the preceding 20 trading days, excluding the evaluation day. | breakout_high , breakout_low , within_range | Yes |
| 5 | Trend direction | Price trend | Close | Fit a linear trend to 20-day close prices; use /day as the trend-label threshold. | uptrend , downtrend , sideways | Yes † |
| 6 | Volatility | Return variability | Close | Compute annualized standard deviation of recent returns. | high_volatility , medium_volatility , low_volatility | No |
| Diagnostic | AC1 | Precision | Recall | F1 |
|---|---|---|---|---|
| UCR | 0.71 | 91.3% | 88.7% | 90.0% |
| RCI | 0.74 | 87.6% | 84.2% | 85.9% |
| ECI | 0.82 | 93.1% | 90.5% | 91.8% |
| Threshold | Diagnostic interpretation |
|---|---|
| Main-paper setting. No evidence filter is applied to directional coverage, so any directional action can contribute. | |
| Minimal evidence threshold. A directional action contributes only when at least one strong chart signal is present. | |
| Stricter evidence threshold. Coverage progressively decreases as directional actions are required to be associated with more strong chart signals. | |
| Conservative endpoint. Coverage approaches zero for all models. The rate of decay reflects how much directional coverage each model retains under increasingly strict evidence requirements. |
| Aggregation | Formula | Key observation |
|---|---|---|
| Product / NDR | Current aggregation; Gemma-4-E2B-It ranks . | |
| Arithmetic mean | with NDR ; Gemma-4-E2B-It rises to rank . | |
| Minimum | with NDR ; improvements outside the weakest component are ignored. | |
| Pareto dominance | – | models are non-dominated, and only about of model pairs can be ordered. |
| Item | Paper-snapshot evidence |
|---|---|
| Stock / date | 601799.SH, 2023-06-30 |
| Input modality | Chart-only (candlestick PNG with MA5/MA10/MA20 and volume) |
| Deterministic OHLCV evidence | |
| MA alignment | Bullish: MA5 , MA10 , MA20 |
| Volume ratio | the 20-day mean (normal volume) |
| Price breakout | Breakout above the prior 20-trading-day high: current close , prior-window high |