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hanabi-1

By REI Network | March 6, 2025

Hanabi-1 is the the first in our "Catalog" series, which specializes in Financial Prediction. Catalog will be a series of transformer models designed to serve a variety of different specialized purposes. The majority of these models will be open-sourced, making them freely available to the developer community. For those requiring programmatic integration, our API will provide a seamless way to incorporate these capabilities into existing workflows as well as plugging them to CORE for improved efficiency.

Introducing Hanabi-1: A Transformer model for Financial Market Analysis

While the industry gravitates toward increasingly large models, our research has revealed that financial market prediction benefits from a more specialized, compact architecture. Hanabi-1 demonstrates how targeted design can outperform brute-force approaches in specific domains like financial time series analysis

With 16.4 million parameter model consists of:

  • 8 transformer layers with multi-head attention mechanisms

  • 384-dimensional hidden states throughout the network

  • Multiple specialized predictive pathways for direction, volatility, price change, and spread

  • Batch normalization rather than layer normalization for better training dynamics

  • Focal loss implementation to address inherent class imbalance

The compact size enables faster inference times and allows us to deploy models at the edge for real-time decision making—critical for high-frequency market environments.

Mathematical Foundations: Functions and Formulas

Positional Encoding

To help the transformer understand sequence ordering, we implement sinusoidal positional encoding:

PE(pos,2i)=sin(pos1100002i/dmodel)PE_{(pos,2i)} = \sin\left(pos \cdot \frac{1}{10000^{2i/d_{model}}}\right)

PE(pos,2i+1)=cos(pos1100002i/dmodel)PE_{(pos,2i+1)} = \cos\left(pos \cdot \frac{1}{10000^{2i/d_{model}}}\right)

Where $pos$ is the position within the sequence and $i$ is the dimension index.

Focal Loss for Direction Prediction

To address the severe class imbalance in financial market direction prediction, we implemented Focal Loss:

FL(pt)=(1pt)γlog(pt)FL(p_t) = -(1 - p_t)^\gamma \log(p_t)

Where $p_t$ is the model's estimated probability for the correct class and $\gamma$ is the focusing parameter (set to 2.0 in Hanabi-1). This loss function down-weights the contribution of easy examples, allowing the model to focus on harder cases.

Confidence Calibration

A key innovation in Hanabi-1 is our confidence-aware prediction system:

Confidence=2pthresholdConfidence = 2 \cdot |p - threshold|

Where $p$ is the predicted probability and $threshold$ is our calibrated decision boundary (0.5). This allows users to filter predictions based on confidence levels, dramatically improving accuracy in high-confidence scenario.

Confidence vs Accuracy
Confidence vs Accuracy

As shown above, predictions with "High" confidence achieve nearly 100% accuracy, while "Very Low" confidence predictions are barely above random chance.

Training Dynamics and Balanced Validation

Training financial models presents unique challenges, particularly the tendency to collapse toward predicting a single class. Our novel validation scoring function addresses this:

ValScore=F1+0.5Accuracy+0.5PRbalance0.1LossBalancepenaltyValScore = F1 + 0.5 \cdot Accuracy + 0.5 \cdot PR_{balance} - 0.1 \cdot Loss - Balance_{penalty}

Where $PR_{balance}$ is the precision-recall balance metric:

PRbalance=min(Precision,Recall)max(Precision,Recall)PR_{balance} = \frac{\min(Precision, Recall)}{\max(Precision, Recall)}

And $Balance_{penalty}$ applies severe penalties for extreme prediction distributions:

if precision == 0 or recall == 0:
    # Heavy penalty for predicting all one class
    balance_penalty = 0.5
elif precision < 0.2 or recall < 0.2:
    # Moderate penalty for extreme imbalance
    balance_penalty = 0.3

This scoring function drives the model toward balanced predictions that maintain high accuracy:

Training Dynamics
Training Dynamics

The plot above reveals how training progresses through multiple phases, with early fluctuations stabilizing into consistent improvements after epoch 80.

Model Architecture Details

Hanabi-1 employs a specialized architecture with several innovative components:

  • Feature differentiation through multiple temporal aggregations:

    • Last hidden state capture (most recent information)

    • Average pooling across the sequence (baseline signal)

    • Attention-weighted aggregation (focused signal)

  • Direction pathway with BatchNorm for stable training:

    • Three fully-connected layers with BatchNorm1d

    • LeakyReLU activation (slope 0.1) to prevent dead neurons

    • Xavier initialization with small random bias terms

  • Specialized regression pathways:

    • Separate networks for volatility, price change, and spread prediction

    • Reduced complexity compared to the direction pathway

    • Independent optimization focuses training capacity where needed

The model's multi-task design forces the transformer encoder to learn robust representations that generalize across prediction tasks.

Prediction Temporal Distribution

Direction Probabilities
Direction Probabilities

The distribution of predictions over time shows Hanabi-1's ability to generate balanced directional signals across varying market conditions. Green dots represent correct predictions, and red dots are incorrect predictions.

Performance and Future Directions

Current performance metrics:

  • Direction accuracy: 73.9%

  • F1 score: 0.67

  • Balanced predictions: 54.2% positive / 45.8% negative

Hanabi-1 currently operates on two primary configurations:

  • 4-hour window model (w4_h1)

  • 12-hour window model (w12_h1)

Both predict market movements for the next hour, with the 12-hour window model showing superior performance in more volatile conditions.

Future developments include:

  • Extending prediction horizons to 4, 12 and 24 hours

  • Implementing adaptive thresholds based on market volatility

  • Adding meta-learning approaches for hyperparameter optimization

  • Integrating on-chain signals for cross-domain pattern recognition

Conclusion

Hanabi-1 demonstrates that specialized, compact transformers can achieve remarkable results in financial prediction tasks. By focusing on addressing the unique challenges of financial data—class imbalance, temporal dynamics, and confidence calibration—we've created a model that delivers reliable signals even in challenging market conditions.

While the model can still be refined, we found that it’s a robust and important first step towards the definition and creation of even more capable financial models.

Follow the github repo for the current implementation and future upgrades:

https://github.com/0xReisearch/hanabi-1