The World Model Is a Market Path Generator
A JeTech research note defining the world model as a synthetic market path generator rather than an offline RL algorithm.
Summary
The JeTech world model is not an offline RL algorithm. It is a market path generator.
past 224 days of OHLC
-> world model
-> next 96 days of OHLC path distributionThe offline RL algorithm comes later:
synthetic OHLC path
-> action or position labeler
-> reward and environment simulator
-> transition dataset
-> IQL, ReBRAC, CQL, TD3+BC, DTThe correct research label is world-model-assisted offline RL or model-based offline RL with synthetic market rollouts. The world model creates the environment and data used for policy learning. It does not learn the policy itself.
A useful trading world model must do more than draw realistic-looking charts. It must preserve volatility clustering, heavy tails, drawdowns, regime duration, gaps, correlations, OHLC validity, and strategy rankings after transaction costs.
What the World Model Learns
In model-based RL, a world model often learns:
p(next_state, reward | state, action)JeTech's current price world model learns:
p(future_ohlc_path | past_ohlc_window)That distinction matters.
| Area | Standard model-based RL | JeTech current world model |
|---|---|---|
| Input | state, action | past OHLC window |
| Output | next state, reward | future OHLC path |
| Action effect | part of dynamics | excluded for now |
| Training | transition model learning | generative time-series learning |
| Use | planning, rollout, value expansion | synthetic market path generation |
For JeTech's medium-horizon OHLC agents, we assume our actions do not move the market. Execution RL and order-book simulation would need action-conditioned dynamics. The current research target is a price-path generator that feeds offline RL.
Link to Model-Based Offline RL
MOPO, MOReL, and COMBO learn dynamics from offline data and use synthetic rollouts. Their warning applies to JeTech: model rollouts become dangerous outside dataset support.
| Method | Main idea | JeTech translation |
|---|---|---|
| MOPO | penalize uncertain model rollouts | attach uncertainty or quality weights to generated paths |
| MOReL | treat uncertain states pessimistically | downweight or reject unrealistic paths |
| COMBO | combine model rollouts with conservative Q learning | use conservative critics on synthetic transitions |
Generated paths should not all receive the same trust. The model is weakest in sparse regimes such as crashes, volatility spikes, and liquidity gaps. If the generator under-samples tails, the agent learns too much leverage. If it over-samples tails, the agent may collapse to flat exposure.
What Makes a Good Market Generator
The generator should match these properties:
| Quality axis | Metrics | Failure mode |
|---|---|---|
| Return distribution | mean, std, skew, kurtosis, quantiles | tails are too thin |
| Volatility clustering | squared-return autocorrelation, realized vol regimes | volatility behaves like independent noise |
| Drawdown | max drawdown, duration, recovery time | no post-crash recovery structure |
| Tail events | gaps, crashes, volatility spikes | rare events vanish or dominate |
| Regime | trend duration, range duration, transition rate | regimes are too short or too long |
| OHLC validity | high and low constraints | invalid candles |
| Cross-asset structure | BTC, ETH, QQQ correlations | individual paths look fine but correlations break |
| Trading utility | strategy ranking, turnover, cost-adjusted return | synthetic winners fail in real data |
The last row matters most. A path generator for policy learning should preserve strategy ranking. If trend following wins in synthetic paths while mean reversion wins in real validation, the world model is a dangerous training environment.
Recent financial diffusion work points in the same direction. Generation of synthetic financial time series by diffusion models applies DDPMs to financial time series and stylized facts. Beyond Visual Realism emphasizes that visual realism does not guarantee strategy-level usefulness. CoFinDiff adds controllable trend and volatility conditions to synthetic financial generation.
Strength of the Current JeTech Structure
The current pipeline separates responsibilities:
1. Train world model on real OHLC
2. Generate synthetic OHLC paths
3. Add exposure through synthetic action labelers
4. Simulate reward and transitions
5. Train offline RL policies
6. Evaluate with real 5Y gateThis separation helps debugging.
| Failure | Likely source |
|---|---|
| unrealistic paths | world model |
| realistic paths but weak policy | action labeler, reward, offline RL |
| synthetic-only performance | synthetic-real transfer gap |
| real tail losses | weak tail generation or reward penalty |
The team can ask whether the offline RL algorithm failed or the market generator failed.
Risks in the Current Structure
Action and Price Are Independent
The current model generates price first, then action labelers attach positions. This is simple, but it weakens the joint relationship between regime and action.
In a crash regime, random actions should have wide loss dispersion. Trend following may enter late. Mean reversion may catch rebounds or catch falling knives. A price-first pipeline can miss these joint patterns.
Short term, labelers should become regime-aware. Medium term, JeTech should test joint transition generation.
Tail Calibration Is Hard
Financial policy survival depends on rare days. If tails are too thin, the policy learns too much risk. If tails are too thick, the policy may stop trading.
Minimum tail checks:
1d / 5d / 20d return quantiles
realized volatility percentiles
gap size distribution
max drawdown distribution
drawdown recovery time
volatility after loss eventsRegime Duration Matters
A model can predict the next candle well and still fail over 96 days. The generated path must preserve trend persistence, range behavior, crash recovery, and volatility decay.
One-step MSE is not enough. JeTech should add multi-horizon return, realized volatility, drawdown shape, and tail quantile metrics.
Likelihood Can Pick the Wrong Model
Likelihood favors common market days. Trading policies need rare regimes too. World model selection should include stylized facts, strategy ranking, tail calibration, and real-gate transfer.
Improvement Plan
A. Path Quality Report
After each world model run, generate samples and compare them with validation data.
world_model_quality.json
return_distribution
volatility_clustering
drawdown_distribution
tail_event_frequency
ohlc_validity
regime_duration
strategy_rankingStore distances, not only pass or fail flags: KS distance, Wasserstein distance, quantile error, autocorrelation error.
B. Regime-Conditioned Generation
Add explicit generation conditions:
| Condition | Examples |
|---|---|
| volatility bucket | low, normal, high, crisis |
| trend bucket | uptrend, range, downtrend |
| drawdown state | near high, mild drawdown, deep drawdown |
| macro proxy | risk-on, dollar strength, crypto beta |
This lets the training pipeline oversample rare but important states.
C. Joint Transition Generator
The medium-term target is complete transition generation:
current:
past OHLC -> future OHLC
future OHLC + labeler -> action and reward transitions
target:
past trajectory + policy archetype
-> OHLC, action, reward, next observation, doneDAWM shows one recent direction: generate state-reward trajectories with a diffusion world model and infer missing actions with inverse dynamics. JeTech does not need to copy it, but the final system should not keep price and action fully isolated.
D. Synthetic-to-Real Gate
World models should not be promoted by standalone metrics alone.
| Gate | Question |
|---|---|
| Distribution gate | do stylized facts match real validation |
| Strategy gate | does simple strategy ranking transfer |
| Policy gate | does the same offline RL algorithm improve on real 5Y |
| Robustness gate | do seeds and sampled paths change conclusions |
Only world models that pass these gates should generate training datasets.
Research Position
The world model is not the trading policy. It creates the market distribution used to train the trading policy.
A useful world model does not maximize synthetic Sharpe. It increases the rate at which trained policies survive the real gate.