options-backtestinglisted

Options positions end in ways you do not control - live or in a backtest: assignment, expiry settlement, pin risk, multi-leg lifecycle, historical chain assembly, and the margin that decides whether the position fits. TRIGGER - backtest a covered call, cash-secured put, wheel, credit spread, iron condor, butterfly, calendar, diagonal, straddle, strangle, PMCC; short option assigned, early exercise, exercise by exception, expires in the money, pin risk, pinned at the strike; historical option chain, options history, chain panel, OSI symbol, adjusted option, non-standard deliverable; 0DTE, weeklies, third Friday, AM vs PM settlement, cash settled index options; option margin, naked margin requirement, portfolio margin, SPAN, buying power reduction; "my options backtest returns look too good"; optopsy, optionlab, an options backtesting library. SKIP for pricing a single option or fitting a vol surface (derivatives-pricing) and for futures rolls (futures-continuous-contracts).
howard-lynn-ye/fin-skills · ★ 1 · Testing & QA · score 77

Install: claude install-skill howard-lynn-ye/fin-skills

# Options backtesting **An equity position ends when you sell it. An options position can end five ways, and you control one of them.** | How it ends | Who decides | |---|---| | You close it | you | | Expires worthless | nobody — clean | | Expires ITM, exercised by exception | the clearing house, by default | | **Assigned early** | **the long side, and you find out afterwards** | | **Pinned at the strike** | **unknown until assignment notices arrive** | A backtest that computes `max(S − K, 0)` at expiry has modelled rows two and three and silently assumed the others never happen. This skill is about what that costs. For **pricing** a single option, Greeks scaling, and vol-surface fitting, go to `../derivatives-pricing/SKILL.md` — including its §6, which carries the measured evidence that `lastPrice` is unusable (54.6% of a live SPY call chain quoted outside its own bid-ask). ## 0. 🚨 Almost nothing in Python backtests options correctly ✅ **Fetched from the PyPI JSON API on 2026-09-04.** Of every package on PyPI (the full index, 884,814 names, was swept), **exactly one models assignment, exercise, settlement and margin: QuantConnect's LEAN.** One more is a genuine multi-leg backtester that explicitly disclaims assignment. Everything else is a pricer, a payoff plotter, or a live-broker SDK. | Package | Latest | Multi-leg | Assignment | Margin | What it actually is | |---|---|---|---|---|---| | **LEAN** (`lean` 1.0.229, 2026-08-28, Apache-2.0; ✅ `lean-cli` 326★, pushed 20