$npx -y skills add agiprolabs/claude-trading-skills --skill kalshi-crypto-index-marketsKalshi daily and hourly range markets on crypto prices (BTC, ETH) and equity indices (S&P 500, Nasdaq-100) — bracket structure, Gaussian P(YES) modeling on price/vol, close-offset decision timing, longshot-sell edge with honest evidence bounds
| 1 | # Kalshi Crypto & Index Range Markets |
| 2 | |
| 3 | Kalshi lists daily (and for crypto, hourly) **range bracket markets** on the level of four liquid underlyings: S&P 500, Nasdaq-100, Bitcoin, and Ethereum. The math is the same partition-and-Gaussian framework as weather brackets — the variable is just price/return and σ comes from the underlying's realized or implied volatility, not a temperature model. |
| 4 | |
| 5 | > Cross-references: for Kalshi API mechanics see `kalshi-api`; for the strategy, sizing, and backtesting framework see `prediction-market-strategy`; for the temperature counterpart see `kalshi-weather-markets`; for the shared bracket/overround formulas see `prediction-markets/references/brackets-and-settlement.md`. |
| 6 | |
| 7 | --- |
| 8 | |
| 9 | ## Series & Market-Type Mapping |
| 10 | |
| 11 | ```python |
| 12 | SERIES_MARKET = { |
| 13 | "KXINX": "index", # S&P 500 index level |
| 14 | "KXNASDAQ100": "index", # Nasdaq-100 index level |
| 15 | "KXBTC": "crypto", # Bitcoin price (USD) |
| 16 | "KXETH": "crypto", # Ethereum price (USD) |
| 17 | } |
| 18 | ``` |
| 19 | |
| 20 | - `market_type = "index"` — daily range only; underlying is the index points level at the official market close. |
| 21 | - `market_type = "crypto"` — daily **and hourly** range markets; BTC and ETH each have multiple hourly events running in parallel with the daily. |
| 22 | |
| 23 | Cadence is higher than weather: crypto hourlies open and settle throughout the day; daily markets open the prior session and settle at the reference close. |
| 24 | |
| 25 | --- |
| 26 | |
| 27 | ## Bracket Structure |
| 28 | |
| 29 | Each event is a **mutually exclusive, collectively exhaustive** partition of the underlying's possible values at settlement: |
| 30 | |
| 31 | - An interior bracket `B<center>` covers a contiguous price band (floor to cap, both-ends-inclusive). Bracket widths are set per-market — read the event's market list; do not assume a fixed width. |
| 32 | - Two open-tail markets anchor the partition: a `less-than` (below the lowest bracket floor) and a `greater-than` (above the highest bracket cap). |
| 33 | - At settlement exactly **one** bracket is YES; all others are NO. |
| 34 | |
| 35 | The overround (sum of all YES prices) is typically > 1.0. The excess is concentrated in the cheap tails — the same favorite–longshot bias seen in weather markets. See `prediction-markets/references/brackets-and-settlement.md` for the overround formula. |
| 36 | |
| 37 | --- |
| 38 | |
| 39 | ## Gaussian P(YES) on Price/Vol |
| 40 | |
| 41 | Given a price forecast distribution `N(μ, σ)` for the underlying at settlement, with bracket covering `[floor, cap]`: |
| 42 | |
| 43 | ``` |
| 44 | # interior bracket |
| 45 | P(YES) = Φ((cap − μ) / σ) − Φ((floor − μ) / σ) |
| 46 | |
| 47 | # open-tail, "greater than cap" |
| 48 | P(YES) = 1 − Φ((cap − μ) / σ) |
| 49 | |
| 50 | # open-tail, "less than floor" |
| 51 | P(YES) = Φ((floor − μ) / σ) |
| 52 | ``` |
| 53 | |
| 54 | `Φ` is the standard normal CDF. Unlike temperature brackets (which settle on integers), price brackets settle on a continuous reference price — the half-integer continuity correction used for weather is **not applicable here**. Do not add ±0.5. |
| 55 | |
| 56 | ### Sourcing σ |
| 57 | |
| 58 | - **Realized vol:** rolling 5- or 20-day realized volatility of the underlying, scaled to the settlement horizon. |
| 59 | - **Implied vol:** the ATM IV from listed options (SPX/NDX for index, CME/Deribit for crypto) is a forward-looking σ that already embeds the market's distributional view for the horizon. |
| 60 | - **Hourly markets:** for BTC/ETH hourlies, σ is the 1-hour IV or intraday realized vol. Σ shrinks rapidly — even small absolute moves land in a different bracket. Sensitivity is high; prefer IV-derived σ. |
| 61 | |
| 62 | For daily markets, a simple log-return diffusion gives `σ_daily ≈ σ_annual / √252` for index, or the equivalent annualized vol / √365 for crypto. Express in price units (not %) before inserting into the formula. |
| 63 | |
| 64 | --- |
| 65 | |
| 66 | ## Decision Timing — Close-Offset, Not a City Hour |
| 67 | |
| 68 | **This is the key difference from weather markets.** |
| 69 | |
| 70 | Weather settles on a daily extreme that occurs at some unknown intraday time. The decision book is read near the likely peak/trough (a city-local hour). |
| 71 | |
| 72 | Crypto and index markets settle at a **fixed reference close**: |
| 73 | |
| 74 | - Daily S&P 500 / Nasdaq-100: the official market close (4:00 PM ET). |
| 75 | - Daily BTC/ETH: a defined reference close published in the market's rulebook. |
| 76 | - Hourly BTC/ETH: the close of each hour interval per the rulebook. |
| 77 | |
| 78 | The practical convention used in production: |
| 79 | |
| 80 | ```python |
| 81 | DECISION_OFFSET_MINUTES = 120 # read book ~2h before settlement close |
| 82 | decision_ts = settlement_close_ts - timedelta(minutes=DECISION_OFFSET_MINUTES) |
| 83 | ``` |
| 84 | |
| 85 | This offset balances information freshness (IV and order-book signal) against the risk of being front-run by news that drops in the final window. Tune per-series based on your fill-rate observations. |
| 86 | |
| 87 | --- |
| 88 | |
| 89 | ## Settlement — Verify the Rulebook Reference |
| 90 | |
| 91 | Settlement is on Kalshi's own `result` field. **Do not re-derive from an external feed.** The exact reference pric |