docs: update README for v0.1.0 release

- Add HMM regime filtering section and examples
- Add covered call / stock-leg strategy mentions
- Update signal count (40+ → 67) and strategy count (31 → 32)
- Update pre-release notice
- Add hmm_regime() to formula DSL examples

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: michaelchu

README.md

@@ -7,16 +7,17 @@
 A high-performance options and stock backtesting engine exposed as an [MCP](https://modelcontextprotocol.io/) server. Connect it to Claude Desktop, Claude Code, or any MCP-compatible client and backtest strategies, optimize parameters, and analyze price patterns through natural language.
 
 > [!NOTE]
-> This project is currently in a pre-release state. We are iterating quickly, which means breaking changes to the API and configuration may occur without prior notice. Use in production environments at your own risk.
+> This project is under active development. Breaking changes to the API and configuration may occur between minor versions. Pin to a specific release tag for stability.
 
 ## What You Can Do
 
 ### Backtest Options Strategies
 
-Run event-driven simulations across 31 built-in options strategies — from simple singles to multi-leg iron condors, butterflies, calendars, and diagonals. Full position management with stop-loss, take-profit, max-hold exits, and 5 dynamic position sizing methods.
+Run event-driven simulations across 32 built-in options strategies — from simple singles to multi-leg iron condors, butterflies, calendars, diagonals, and stock-leg strategies (covered calls, protective puts). Full position management with stop-loss, take-profit, max-hold exits, and 5 dynamic position sizing methods.
 
 ```
 "Backtest an iron condor on SPY with $100k capital, 30-delta wings, and a 50% stop loss"
+"Run a covered call strategy on AAPL with a 30-delta short call"
 "Run a short put selling strategy with RSI < 30 as the entry filter"
 ```
 
@@ -47,6 +48,16 @@ Walk-forward analysis with rolling train/test windows and permutation testing fo
 "Is this backtest result statistically significant or just luck?"
 ```
 
+### Filter by Market Regime
+
+Gate entries using Hidden Markov Model regime detection. Fit on historical data, classify forward in real-time (no look-ahead bias), and only trade in favorable regimes.
+
+```
+"Only enter covered calls when SPY is in a bullish HMM regime"
+"Skip trades during bearish regimes: hmm_regime(3, 5) != bearish"
+"Combine regime with technicals: hmm_regime(2, 5) == bullish and rsi(close, 14) < 30"
+```
+
 ### Analyze Price Patterns
 
 Discover seasonality and time-based patterns with aggregate statistics, distribution analysis, correlation matrices, rolling metrics, and regime detection.
@@ -59,7 +70,7 @@ Discover seasonality and time-based patterns with aggregate statistics, distribu
 
 ### Build Custom Signals
 
-Create entry/exit signals with a formula DSL covering 35+ functions (momentum, trend, volatility, volume, derived stats). Save, rename, and reuse signals across sessions.
+Create entry/exit signals with a formula DSL covering 67 functions (momentum, trend, volatility, volume, regime, derived stats). Save, rename, and reuse signals across sessions.
 
 ```
 "Create a signal that fires when RSI < 30 and price is below the lower Bollinger Band"
@@ -71,7 +82,7 @@ Create entry/exit signals with a formula DSL covering 35+ functions (momentum, t
 | Tool | Description |
 |------|-------------|
 | `list_symbols` | Discover available symbols in the data cache |
-| `list_strategies` | Browse all 31 built-in options strategies with leg definitions |
+| `list_strategies` | Browse all 32 built-in options strategies with leg definitions |
 | `build_signal` | Create, validate, save, rename, search, and manage custom signals (CRUD + catalog) |
 | `run_options_backtest` | Full event-driven options simulation with trade log and metrics |
 | `run_stock_backtest` | Signal-driven stock/equity backtest on OHLCV data |
@@ -84,7 +95,7 @@ Create entry/exit signals with a formula DSL covering 35+ functions (momentum, t
 | `distribution` | Return distribution analysis with normality testing |
 | `correlate` | Cross-symbol or cross-metric correlation matrices |
 | `rolling_metric` | Rolling window calculations (Sharpe, volatility, returns, etc.) |
-| `regime_detect` | Market regime detection using volatility or returns clustering |
+| `regime_detect` | Market regime detection (volatility clustering, trend state, Gaussian HMM) |
 | `generate_hypotheses` | Auto-scan for statistically significant patterns with FDR correction |
 | `portfolio_backtest` | Run multiple stock strategies as a weighted portfolio |
 | `drawdown_analysis` | Full drawdown distribution with episode tracking and Ulcer Index |
@@ -133,9 +144,9 @@ To change the cache directory, set `DATA_ROOT` in the config:
 
 ## Key Capabilities
 
-### 31 Options Strategies
+### 32 Options Strategies
 
-Singles, verticals, straddles, strangles, butterflies, condors, iron condors/butterflies, calendars, and diagonals — with multi-expiration support for calendar and diagonal spreads.
+Singles, verticals, straddles, strangles, butterflies, condors, iron condors/butterflies, calendars, diagonals, and stock-leg strategies (covered call, protective put) — with multi-expiration support for calendar and diagonal spreads.
 
 ### 4 Slippage Models
 
@@ -145,9 +156,9 @@ Mid, spread (bid/ask worst-case), liquidity-based (volume-scaled), and per-leg f
 
 Fixed quantity, fixed fractional, risk per trade, Kelly criterion, and volatility targeting.
 
-### 40+ Built-in Signals
+### 67 Built-in Signals
 
-RSI, MACD, Stochastic, Bollinger Bands, Keltner Channels, Supertrend, Aroon, ATR, OBV, MFI, IV Rank/Percentile, and more — plus AND/OR/NOT combinators and cross-symbol signals (e.g., VIX as a filter for SPY trades).
+RSI, MACD, Stochastic, Bollinger Bands, Keltner Channels, Supertrend, Aroon, ATR, OBV, MFI, IV Rank/Percentile, HMM regime filter, and more — plus AND/OR/NOT combinators and cross-symbol signals (e.g., VIX as a filter for SPY trades).
 
 ### Formula DSL
 
@@ -158,10 +169,11 @@ close > sma(close, 50) and rsi(close, 14) < 30
 macd_hist(close) > 0 and rel_volume(volume, 20) > 2.0
 consecutive_down(close) >= 3 and volume > sma(volume, 20) * 1.5
 iv_rank(iv, 252) > 50 and bbands_lower(close, 20) > close
+hmm_regime(3, 5) == bullish and rsi(close, 14) < 30
 day_of_week() == 1 and pct_change(close, 1) < -0.005
 ```
 
-Supports lookback (`close[1]`), date/time functions (`day_of_week()`, `month()`, `hour()`), conditionals (`if(cond, then, else)`), and 35+ rolling/statistical functions.
+Supports lookback (`close[1]`), date/time functions (`day_of_week()`, `month()`, `hour()`), conditionals (`if(cond, then, else)`), HMM regime gating (`hmm_regime()`), cross-symbol references (`VIX > 20`), and 67 rolling/statistical functions.
 
 ## Data