JEV INVESTMENT LAB
Real market data. Real decisions. Historical experiment.
NIFTY 100 UNIVERSE
EXPERIMENTAL — NOT INVESTMENT ADVICE
DECISION-MAKING EXPERIMENT
JEV-20260922-V2
A historical simulation that asks whether a structured decision model can repeatedly choose under uncertainty — using stock investing as the test bed, not as a product.
WHY THIS EXPERIMENT?
Jev is a new class of AI model designed to make structured decisions rather than generate traditional text.
I wanted to test a simple question:
“How good is Jev at making difficult decisions when given a large amount of context, a defined set of choices, and real constraints?”
Stock investing is a useful test case because decisions are:
- uncertain
- sequential
- context dependent
- constrained by capital
- affected by previous decisions
- evaluated over time rather than on a single question
This experiment uses stock investing as a decision-making test bed. It is not intended to provide financial advice or demonstrate an automated trading strategy.
EXPERIMENTAL — NOT INVESTMENT ADVICE
This is a historical simulation designed to explore AI decision-making. It is not a recommendation to buy or sell securities and is not an automated trading system.
WHAT IS THIS EXPERIMENT TESTING?
INPUT
- Market data
- Technical context
- Portfolio state
- Available capital
- Decision constraints
↓→
JEV
- Structured decision model
- typesafe-ai/jev
↓→
DECISION
- BUY
- HOLD
- SELL
- NO ACTION
↓→
PORTFOLIO
- Holdings change
- Cash changes
- Value marked at close
1.Can Jev make decisions repeatedly rather than answer a single question?
2.Can it make decisions while respecting portfolio constraints?
3.Can it incorporate changing market and portfolio context?
4.Can it decide when to enter and exit positions?
5.How does its decision-making behave over a sustained historical replay?
The experiment evaluates the quality and behavior of the decisions produced by Jev. Portfolio return is an outcome of the simulation, not the sole definition of decision quality.
EXPERIMENT SCOPE
CAPITAL
₹10,00,000
UNIVERSE
NIFTY 100 (current)
PERIOD
2026-03-10 → 2026-08-31
TRADING SESSIONS
118
MODEL
typesafe-ai/jev
DECISION FREQUENCY
End of each trading session
EXECUTION
Next trading session OPEN
DECISION OPTIONS
BUY / HOLD / SELL / NO ACTION
MAX POSITIONS
5
MAX INITIAL POSITION ALLOCATION
20%
LEVERAGE
None
SHORTING
None
TRANSACTION COST
10 bps
SLIPPAGE
5 bps
BENCHMARK
NIFTY 100 buy-and-hold
EXPERIMENT GUIDELINES
These rules were frozen before the replay and were not changed based on observed results.
- Jev evaluates eligible stocks at EOD.
- BUY on an unheld stock can initiate a position.
- BUY on an already-held stock does not add shares.
- HOLD maintains the existing state.
- SELL exits the entire existing position.
- SELL on an unheld stock does nothing.
- NO ACTION leaves the portfolio unchanged.
- Maximum 5 positions.
- Sell decisions are processed before new buys.
- A position slot is freed only after a sell actually executes.
- New buys are executed at the next trading session OPEN.
- Portfolio is marked using CLOSE.
- No leverage.
- No shorting.
- Transaction costs and slippage are included.
- Remaining capital stays in cash.
No future market information is supplied to Jev for a decision.
WHAT INFORMATION DID JEV RECEIVE?
For each eligible stock on each decision date, Jev received structured market context and the live portfolio state — only information available as of that session’s close.
MARKET CONTEXT
- 1 / 5 / 20 / 60 day returns
- SMA 20 / 50 / 200
- RSI
- Volatility
- Volume / volume ratio
- Distance from 52-week high
- Drawdown
- NIFTY 100 market returns
- Relative performance
PORTFOLIO CONTEXT
- Current holdings
- Available cash
- Portfolio constraints
- Current position state
↓→
JEV DECISION
- BUY
- HOLD
- SELL
- NO ACTION
RESULT
Jev simulated return
+12.25%
NIFTY 100
+1.11%
Trades
19
Successful decisions
10,299
Max positions
5
The result surprised me — but the return is not the experiment’s only output. The more interesting question is what Jev actually decided, when it decided it, and why those decisions produced this portfolio path.
CAN WE TRUST THE REPLAY?
The V2 experiment was independently audited after completion.
- Trade-level accounting✓ PASS
- Portfolio reconstruction✓ PASS
- Constraint validation✓ PASS
- Yahoo raw OPEN validation✓ PASS
- Benchmark reconciliation✓ PASS
EXPERIMENT PORTFOLIO
₹11,22,524.610143
INDEPENDENT RECONSTRUCTION
₹11,22,524.610143
DIFFERENCE
₹0
The experiment database and methodology were not modified during the audit.
External NSE reference data was requested for all 19 trades, but NSE returned HTTP 503 for those requests. Those reference fields are therefore recorded as unavailable; the experiment’s Yahoo Finance data was not replaced.
Open the audit explorer →IMPORTANT LIMITATIONS
This is an experiment, not evidence that Jev can reliably outperform the market.
- Historical simulation only.
- 118 trading sessions is a short evaluation window.
- The universe uses current NIFTY 100 membership, introducing survivorship bias.
- Yahoo Finance data is an experimental data source and is not an authoritative commercial market-data feed.
- This is not live trading.
- Results do not establish future investment performance.
- The experiment was not designed as financial advice or a deployable trading strategy.
EXPLORE THE EXPERIMENT
1. REPLAY
Watch the experiment unfold session by session.
- • Jev’s decisions
- • portfolio state
- • holdings
- • cash
- • portfolio value
- • trades as they occur
This is the best place to understand the experiment as a sequence of decisions.
2. PORTFOLIO
See how the portfolio evolved over the experiment.
- • portfolio value
- • holdings
- • cash
- • position changes
- • performance versus the benchmark
3. TRADES
Inspect every executed trade.
- • decision date
- • execution date
- • ticker
- • action
- • execution price
- • quantity
- • transaction costs
- • portfolio impact
4. ANALYSIS
Explore the decision behavior behind the result.
- • BUY / HOLD / SELL / NO ACTION behavior
- • decision probabilities
- • selected stocks
- • timing
- • patterns in Jev’s decisions
- • portfolio behavior
5. AUDIT
Verify the experiment rather than simply trusting the headline number.
- • trade accounting
- • portfolio accounting
- • constraints
- • execution prices
- • benchmark calculation
The Overview tells you WHAT happened.
Replay shows you HOW it happened.
Portfolio shows you WHERE the money moved.
Trades shows you WHAT Jev actually did.
Analysis helps understand WHY the decisions matter.
Audit checks WHETHER the result is internally consistent.
DATA & REPRODUCIBILITY
Technical cache details for readers who want the underlying market-data footprint. This section is secondary to the decision-making story above.
MARKET DATA CACHE
Local Yahoo Finance cache behind JEV-20260922-V2. Experiment window uses sessions from 2026-03-10 through 2026-08-31.
Stocks cached
100 / 100
Trading sessions in cache
384
Failed downloads
0
Cache as of
2026-09-22
SOURCE
VendorYahoo Finance · yahoo-finance2 4.0.2
UniverseFixed current NIFTY 100 universe
Constituent filedata/universe/ind_nifty100list.csv
BenchmarkNIFTY 100 (^CNX100)
Session clockAsia/Kolkata
Report time22/9/2026, 20:56:58 IST
CACHE WINDOW
First session requested2025-03-03
First trading session2025-03-03
Last trading session2026-09-22
Experiment start2026-03-10
Experiment end2026-08-31
Placeholder sessions excluded2026-01-15, 2026-05-01, 2026-05-28, 2026-06-26, 2026-09-14
ADJUSTMENT
Yahoo reported 9 split events. Overnight close ratios classify 9 as already split-adjusted and 0 as unadjusted traded prices. Dividend events: 259. Symbols where adj_close differs from close: 95. A split-adjusted history downloaded on 2026-09-22 embeds split factors whose ex-date is after a simulated decision date. That changes the rupee level, not the split-adjusted return. `adj_close` also embeds later dividends and is not a point-in-time price.
LATER LISTINGS
| Symbol | First real session | Sessions before listing |
|---|---|---|
| ENRIN | 2025-06-19 | 72 |
| TATACAP | 2025-10-13 | 151 |
| TMCV | 2025-11-12 | 171 |
SAMPLE BARS
Reliance Industries Ltd. RELIANCE.NS
| Date | Open | High | Low | Close | Adj close | Volume |
|---|---|---|---|---|---|---|
| 2025-03-03 | 1,204 | 1,206.45 | 1,156 | 1,171.25 | 1,161.22 | 1,79,44,938 |
| 2025-03-04 | 1,162.2 | 1,174 | 1,159.55 | 1,161.9 | 1,151.95 | 1,13,77,373 |
| 2025-03-05 | 1,161 | 1,183 | 1,157 | 1,175.6 | 1,165.53 | 86,64,095 |
| 2026-09-18 | 1,245 | 1,247.3 | 1,226.4 | 1,226.4 | 1,226.4 | 1,51,22,715 |
| 2026-09-21 | 1,234.1 | 1,249.1 | 1,232.5 | 1,247.4 | 1,247.4 | 1,00,07,218 |
| 2026-09-22 | 1,247.6 | 1,251.9 | 1,237.4 | 1,240.4 | 1,240.4 | 1,06,81,733 |
HDFC Bank Ltd. HDFCBANK.NS
| Date | Open | High | Low | Close | Adj close | Volume |
|---|---|---|---|---|---|---|
| 2025-03-03 | 869.9 | 871.53 | 847.05 | 850.78 | 825.77 | 2,12,05,364 |
| 2025-03-04 | 849 | 857.15 | 846.63 | 855 | 829.87 | 1,99,20,958 |
| 2025-03-05 | 850.98 | 855.4 | 844.13 | 845 | 820.17 | 2,15,83,872 |
| 2026-09-18 | 715.25 | 733.8 | 715.25 | 731 | 731 | 3,94,00,710 |
| 2026-09-21 | 731 | 742.65 | 729.05 | 739.5 | 739.5 | 3,54,82,683 |
| 2026-09-22 | 738.85 | 749.3 | 738.6 | 738.6 | 738.6 | 3,54,73,028 |
Infosys Ltd. INFY.NS
| Date | Open | High | Low | Close | Adj close | Volume |
|---|---|---|---|---|---|---|
| 2025-03-03 | 1,692.3 | 1,728.6 | 1,692.3 | 1,708.6 | 1,624.34 | 75,04,969 |
| 2025-03-04 | 1,695 | 1,699 | 1,670 | 1,688.3 | 1,605.04 | 67,59,673 |
| 2025-03-05 | 1,692.45 | 1,732.95 | 1,692.45 | 1,711.5 | 1,627.1 | 81,80,782 |
| 2026-09-18 | 1,061.9 | 1,061.9 | 1,038 | 1,051.4 | 1,051.4 | 2,21,24,953 |
| 2026-09-21 | 1,041.5 | 1,044.5 | 1,030.3 | 1,038.5 | 1,038.5 | 60,74,358 |
| 2026-09-22 | 1,037.7 | 1,041 | 1,019.2 | 1,029.4 | 1,029.4 | 93,38,840 |
INDUSTRIES IN THE FILE
- Financial Services23
- Automobile and Auto Components9
- Capital Goods9
- Fast Moving Consumer Goods8
- Healthcare8
- Metals & Mining7
- Information Technology6
- Oil Gas & Consumable Fuels6
- Power6
- Construction Materials4
- Consumer Services4
- Chemicals2
- Consumer Durables2
- Realty2
- Services2
- Construction1
- Telecommunication1