> For the complete documentation index, see [llms.txt](https://usefelix.gitbook.io/perps/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://usefelix.gitbook.io/perps/getting-started/perp-specifications/usa100.md). # USA100 ### Times Two windows make up for weekday coverage: * Regular-hours: 6:00 p.m. – 5:00 p.m. ET * Off-hours: 5:00 p.m. – 6:00 p.m. ET Weekend coverage starts on Friday 5:00 p.m. ET. and runs continuously until Sunday 6:00 p.m. ET. ### Oracle Price Methodology Oracle pricing is used to calculate funding rates which anchor perpetual contract price to underlying commodity price. For the 24/7 markets we divide the oracle price into three segments (weekday on-hours, weekday off-hours, weekend off-hours). Pricing infrastructure is handled by Redstone. Each oracle update (every 2.5s) can change oraclePx by at most 1%. **EMA Definition (used below)** Let $$x\_t$$be the input series sampled every $$\Delta t = 1\mathrm{s}$$, and let $$S\_t$$ be the EMA with time constant $$\tau\ (\text{e.g., }1\mathrm{h},8\mathrm{h},150\mathrm{s}).$$ We use: $$ % EMA recursion + smoothing factor S\_t = \beta S\_{t-1} + (1-\beta),x\_t, \qquad \beta = \exp!\left(-\frac{\Delta t}{\tau}\right) $$ **Part 1: Weekday on-hours (Weekdays from 6 PM ET to 5 PM ET)** We use current contract when deriving the implied spot price as per the roll schedule. To derive the implied spot price we use the standard cost-to-carry model which is described as follows for NQ100: S = F\*exp(−(r-q)T) Where: * F = future price for maturity T * S = spot price * r = risk-free interest rate (annual, continuously compounded) * q = annualized dividend yield * T = time to maturity in years For NQ100, we define these values at the time of writing (23rd March) as: * F = price of NQM26 * r = 4.4% * q = 0.7% * T = 88/365 The cost-to-carry model depends on the values of r and q which can change over time as the macro-economic conditions evolve. We will update these values daily so that they stay in line with the actual spot prices and the users get a good trading experience. This calculated implied spot price is then pushed to the oracle price directly approximately every 3 seconds. **Part 2: Weekday off-hours** Oracle = EMA\_30m(impact\_price) **Part 3: Weekend off-hours** Oracle = EMA\_4h(impact\_price) ### Mark Pricing This section details our methodology for calculating the mark price, which serves as the reference for margin, liquidations, take-profit and stop-loss triggers, and unrealized profit and loss computations. Pricing infrastructure is handled by Redstone. Each oracle update (every 2.5s) can change markPx by at most 1%. Mark Price is calculated as the median of the following 3 values: * MarkPx0: Oracle Price * MarkPx1: Oracle Price * MarkPx2: The median of best bid, best ask, last trade on Hyperliquid (added as default by HL) ### ExternalPerpPx Pricing This limits a perp market's mark price movement to the given band of +/- min(1/max\_leverage, 20%) from the externalPerpPx value. **Part 1: Weekday on-hours** Oracle Price **Part 2: Weekday off-hours** Last Close from Weekday On Hour period **Part 3: Weekend off-hours** Last Close on Weekday On Hour #### **Roll Over Methodology** There will be 3 updates when going from previous contract to the next as per the following schedule (assuming current contract expires on 27th of Feb (Friday)): * 20 business days before the expiry of current contract (30th Jan Friday) we will define the oracle price to be: 0.75*current\_contract + 0.25*next\_contract * On 2nd Feb (Monday; next business day) we will define the oracle price to be: 0.50*current\_contract + 0.5*next\_contract * On 3rd Feb (Tuesday) we will define the oracle price to be: 0.25*current\_contract + 0.75*next\_contract * On 4th Feb (Wednesday) the oracle price will represent the next\_contract fully Each of the above update should be made at 4:30 PM ET of the specified day. For USA100 we will be rolling over 4 times a year. The roll will follow these contracts: Z → H → M → U → Z and so on. ### Holidays * Holidays are treated as weekends. Shorter regular sessions due to holidays will transition to weekend status afterwards. Holidays are defined here: