> ## Documentation Index > Fetch the complete documentation index at: https://docs.everstrike.xyz/llms.txt > Use this file to discover all available pages before exploring further. # Perpetual Options: Dynamic-Strike Options Without Expiry > Trade no-expiry BTC options with strike prices pinned to the 100-hour EMA. Get delta, gamma, vega, and theta exposure — all margined in evUSD. Perpetual options give you continuous delta, gamma, vega, and theta exposure to an underlying asset without ever picking an expiration date. Instead of a fixed strike price that eventually goes stale, perpetual options use a dynamic strike price that tracks the 100-hour Exponential Moving Average (EMA₁₀₀) of the underlying asset — keeping every contract relevant indefinitely. On Everstrike, perpetual options are priced, margined, and cash-settled in [evUSD](/account/evusd), so no physical delivery of the underlying asset ever takes place. ## Specification | Field | Value | | ---------------------------- | ------------------------------- | | Settlement | Cash | | Expiration | Perpetual | | Pricing Currency | evUSD | | Margin Currency | evUSD | | Settlement Currency | evUSD | | Funding | Hourly | | Funding Interval | 1h | | Max Funding Rate | 10% | | Funding Period | 10h | | Strike Price | EMA₁₀₀ (Underlier) × Multiplier | | Strike Price Update Interval | 5 seconds | ## Strike Prices Perpetual options on Everstrike use dynamic strike prices. Rather than listing new contracts every time the market moves, Everstrike anchors each strike price to EMA₁₀₀ of the underlying asset multiplied by a fixed per-contract offset. This design eliminates de-listings and keeps the entire options chain stable over time. ### Strike Price Multipliers Each of the nine available multipliers defines one contract in the options chain: ``` 0.90 × EMA₁₀₀ (Underlier) 0.95 × EMA₁₀₀ (Underlier) 0.97 × EMA₁₀₀ (Underlier) 0.99 × EMA₁₀₀ (Underlier) 1.00 × EMA₁₀₀ (Underlier) 1.01 × EMA₁₀₀ (Underlier) 1.03 × EMA₁₀₀ (Underlier) 1.05 × EMA₁₀₀ (Underlier) 1.10 × EMA₁₀₀ (Underlier) ``` ### EMA₁₀₀ Formula EMA₁₀₀ is the 100-hour Exponential Moving Average of the contract's underlying asset, calculated as: ``` EMA₁₀₀ = EMA_100[Pₜ, Pₜ₋₁, … Pₜ₋₉₉] ``` Where: * `EMA_100` — 100-length Exponential Moving Average * `Pₜ` — Everstrike Index Price right now * `Pₜ₋₁` — Everstrike Index Price 1 hour ago * `Pₜ₋₉₉` — Everstrike Index Price 99 hours ago Strike prices update every **5 seconds** as EMA₁₀₀ evolves. ### Benefits of Dynamic Strike Prices * You can trade the same contract years from now that you trade today. * Contracts are never de-listed — you will never be forced to close a position because a contract was removed. * The options chain is completely stable: the same 18 contracts, forever. The tradeoff is that strike price movement itself affects your P/L. [Drift](/trading/drift) helps you measure that effect. ## Funding Funding is an hourly exchange of money between longs and shorts that keeps perpetual option prices anchored to their fair value. When the funding rate is positive, longs pay shorts; when it is negative, shorts pay longs. **Funding formulas:** ``` Funding (Long) = -Funding Rate × Position Size (USD) Funding (Short) = Funding Rate × Position Size (USD) ``` Funding is exchanged during the **first five seconds** of each hour. Everstrike snapshots all open positions at that moment and debits or credits each trader's margin balance accordingly. Trading is **disabled for the first ten seconds** of each hour while the funding exchange settles. ### Funding Rate Calculation **Step 1 — Calculate the Premium:** ``` Premium = (Mark Price - Index Price) / Index Price ``` * `Mark Price` — the current trading price of the perpetual option. * `Index Price` — the spot reference price of the underlying asset. * `Premium` — the relative difference between the two. **Step 2 — Calculate the Base Funding Rate:** ``` Base Funding Rate = Max(dampener, Premium) + Min(dampener, Premium) ``` For perpetual options, `dampener = 1.00` (100%). **Step 3 — Calculate the Funding Rate:** ``` Funding Rate = Base Funding Rate × (Funding Interval / Funding Period) = Base Funding Rate × (1h / 10h) ``` The hourly funding rate is capped at **10%**. ## Drift Drift is unique to floating-strike instruments such as perpetual options. It measures how movement in the strike price affects the intrinsic value of your position — expressed as an expected hourly percentage change in intrinsic value attributable solely to strike price movement. * A Drift of **+2%** means strike price movement is increasing intrinsic value by approximately 2% per hour. * A Drift of **-2%** means the opposite — intrinsic value is eroding at approximately 2% per hour from strike price movement. Drift is often correlated with the funding rate: a negative Drift typically accompanies a negative funding rate. Everstrike displays Drift alongside the funding rate in the trading UI. Unlike funding, Drift is **informational only** — no transfers ever take place because of Drift. Read more in [Drift](/trading/drift). ## Settlement Perpetual options are cash-settled. When you close a position, Everstrike immediately realizes your P/L and credits it to your cash balance — usually within one second of closing. No physical delivery of the underlying asset ever takes place. ## Examples ### Example 1 — Long Call A trader buys a perpetual BTC call option for **\$100**. The strike price is pinned to EMA₁₀₀(BTC). At entry, EMA₁₀₀(BTC) is **22,000** and BTC trades at **22,100**. Twelve hours later, EMA₁₀₀(BTC) has risen to **22,100** and BTC trades at **22,500**. The trader has paid **\$100** in funding. ``` Net P/L = $22,500 - $22,100 - $100 - $100 = $200 ``` This amount is credited to the trader's cash balance on close. ### Example 2 — Long Put A trader buys a perpetual BTC put option for **\$10**. The strike price is pinned to EMA₁₀₀(BTC). At entry, EMA₁₀₀(BTC) is **22,000** and BTC trades at **22,100**. Twelve hours later, EMA₁₀₀(BTC) has risen to **22,100** and BTC trades at **21,500**. The trader has paid **\$300** in funding. ``` Net P/L = $22,100 - $21,500 - $10 - $300 = $290 ``` This amount is credited to the trader's cash balance on close. **Equivalence with perpetual futures:** A perpetual call option with a strike price of zero is functionally equivalent to a perpetual futures contract. Both share the same payoff function, and funding works identically across the two product types. See [Perpetual Futures](/products/perpetual-futures) for details.