Expected Value Calculator (Free)
Calculate expected value for stock positions using scenario-based modeling. Combines options data, earnings history, and short interest to size positions with mathematical discipline.
What it does
For each position, builds probability-weighted scenarios:
- Bull case: Catalyst-driven upside (earnings beat, sector rotation, short squeeze)
- Base case: Normal trading range continuation
- Bear case: Downside risks (earnings miss, macro shock, sector rotation out)
Weights scenarios by:
- Options sentiment (real calls vs puts, excluding lottery)
- Historical earnings surprise patterns
- Short interest level and squeeze potential
- Sector momentum
Usage
Calculate expected value for my portfolio:
- RXRX: 500 shares @ $3.26, stop-loss $2.85
- KTOS: 200 shares @ $56.99, stop-loss $52.00
- TEM: 100 shares @ $48.46, stop-loss $49.75
Use 3 scenarios (bull/base/bear) with probabilities.
Include confidence level and data quality assessment.
Example Output
=== EV Analysis — 2026-05-13 ===
RXRX $3.26 | Position: $1,630
Bull (30%): $4.80 → +47.2% → EV: +$770
Base (45%): $3.40 → +4.3% → EV: +$63
Bear (25%): $2.85 → -12.6% → EV: -$205
─────────────────────────────────
Weighted EV: +$628 (+38.5%) [HIGH confidence]
Note: Options P/C 0.38 supports bull case. 84% lottery calls stripped.
KTOS $56.99 | Position: $11,398
Bull (35%): $68.00 → +19.3% → EV: +$770
Base (40%): $58.50 → +2.6% → EV: +$121
Bear (25%): $52.00 → -8.8% → EV: -$249
─────────────────────────────────
Weighted EV: +$642 (+5.6%) [MEDIUM confidence]
Note: Sector (defense) momentum positive. IV elevated at 170%.
TEM $48.46 | Position: $4,846
Bull (25%): $56.00 → +15.6% → EV: +$188
Base (40%): $49.00 → +1.1% → EV: +$22
Bear (35%): $49.75 → +2.7% → EV: STOP
─────────────────────────────────
Weighted EV: -$41 (-0.8%) [LOW confidence]
⚠️ BELOW STOP-LOSS — review position
Confidence Levels
- HIGH: Multiple confirming signals (options flow + technicals + news)
- MEDIUM: 1-2 signals, others neutral or missing
- LOW: Conflicting signals or insufficient data
Pro Version
Free version uses basic scenario modeling with manual probability inputs.
Full bundle — $29 one-time: Polygon.io options data integration, real/lottery separation, per-expiry analysis, anomaly detection, automatic probability weighting from live data. → https://jaehyunpark.gumroad.com/l/tcyahy
Author
Production EV engine used daily for real portfolio decisions. The TEM example above is real — the EV turned negative the morning before the stop-loss was hit.