---
name: Derivatives & Stablecoin Design Patterns
description: Use this skill when designing or auditing perpetual futures, options protocols, CDP stablecoins, or algorithmic stablecoin mechanisms — to understand funding rate math, liquidation design, collateral ratio dynamics, and death-spiral prevention.
ecosystem: ethereum
type: defi-guide
source: community
confidence: high
version: 1.0.0
time_sensitivity: evergreen
tags:
  - derivatives
  - perpetuals
  - options
  - stablecoin
  - cdp
  - algorithmic-stablecoin
  - defi-patterns
  - funding-rate
updated_at: 2026-03-26T00:00:00.000Z
---

# Derivatives & Stablecoin Design Patterns

Distilled from DeFiLlama data covering derivatives protocols ($2.39B TVL: Jupiter $877M, Hyperliquid HLP $433M, Drift $323M, GMX V2 $261M, dYdX $125M) and stablecoin categories (CDPs $9.2B TVL: Sky/MakerDAO $7.3B, Liquity $166M; Algo stables: Frax $63M; dual-token: MoneyOnChain $40M).

---

## Perpetual Futures Design Patterns

Perpetual futures are the highest-volume DeFi derivatives: no expiry, funded continuously to stay near the underlying index.

### 1. Funding Rate Mechanism

Funding rates are the core mechanism that keeps perpetual mark price ≈ index price:

```
fundingRate = (markPrice - indexPrice) / indexPrice * fundingFactor
```

**Payment direction:**
- `markPrice > indexPrice` (longs paying premium): longs pay shorts
- `markPrice < indexPrice`: shorts pay longs

**Typical parameters:**
- Funding interval: every 1 or 8 hours
- Funding factor: 0.01–0.05% per hour (annualizes to 88–438%)
- Clamped: `max(-0.05%, min(0.05%, fundingRate))` to prevent runaway funding

**Implementation pitfall:** If the funding rate is calculated using an on-chain price (spot AMM) rather than a robust index, it is manipulable. Use aggregated off-chain index prices or a TWAP.

### 2. AMM-Based Perpetuals (GMX V2 Model)

GMX uses a Global Liquidity Pool (GLP) as the counterparty to all traders:

```
Position PnL = (currentPrice - entryPrice) * positionSize * leverage
Trader profit = GLP loss; Trader loss = GLP gain
```

**Key components:**
- **Oracle-priced:** Uses Chainlink + GMX oracle, not pool spot price → no sandwich attacks
- **Borrow fees:** Positions pay hourly fees for holding open positions (`borrowFactor * openInterest / poolSize`)
- **Price impact:** Large orders have price impact to prevent GLP from being adversely selected

**Design risk — GLP insolvency:** If traders are net profitable over a period (e.g., directional market), GLP holders lose. GMX V2 mitigates with asymmetric fees (discount for trades in market-balancing direction).

### 3. Orderbook-Based Perpetuals (dYdX / Hyperliquid)

Orderbook perps match buyers and sellers directly, with a central risk engine managing margin:

```
maintenanceMargin = positionSize * maintenanceMarginFraction
if accountEquity < maintenanceMargin: → liquidation
```

**Liquidation mechanics:**
1. Position is liquidated to insurance fund at mark price
2. If insurance fund insufficient → auto-deleveraging (ADL): profitable counter-positions are force-closed

**Design differences from AMM perps:**
- No impermanent loss for liquidity providers (they earn spread, not directional risk)
- Requires centralized sequencer for order matching (dYdX V4 decentralized this)
- Capital efficiency higher: cross-margin netting

### 4. Virtual AMM (vAMM) Perpetuals (Drift / dYdX V1)

vAMMs use the constant product formula to determine prices without holding real assets:

```
x * y = k (virtual reserves)
markPrice = x / y
```

**Problem with vAMMs:** Virtual reserves diverge from real market prices over time, requiring frequent parameter recalibration. Drift migrated to DLOB (Decentralized Limit Order Book) + JIT (Just-In-Time) liquidity to fix this.

**Key lesson:** vAMMs are a stepping stone design, not a long-term solution for perpetual DEXs.

### 5. Position Sizing & Risk Parameters

Standard risk tiers across major perp protocols:

| Asset | Max Leverage | Initial Margin | Maintenance Margin |
|---|---|---|---|
| BTC/ETH | 20–50× | 2–5% | 1–2.5% |
| Mid-cap alts | 10–20× | 5–10% | 2.5–5% |
| Low-liquidity | 3–5× | 20–33% | 10–20% |

---

## Options Protocol Design Patterns

### 6. On-Chain Options Pricing

Traditional Black-Scholes pricing requires continuous-time math that is expensive on-chain. DeFi options use approximations:

**Bonding curve pricing (Hegic-style):**
```
premium = impliedVolatility * sqrt(timeToExpiry) * optionSize * priceAdjustmentFactor
```

**Pool-based IV:** The AMM's option prices imply a volatility; arbitrageurs enforce that this IV converges to market consensus.

**Common pitfall:** Options priced purely from a thinly traded on-chain pool will have systematically wrong IV. Protocols that don't recalibrate IV from off-chain market data will be arbitraged continuously.

### 7. Options Settlement

**Cash settlement:** Settles in stablecoin based on price difference. No physical token delivery needed.

```solidity
function exercise(uint256 optionId) external {
    Option storage opt = options[optionId];
    require(block.timestamp >= opt.expiry, "not expired");
    int256 pnl = int256(oracle.getPrice()) - int256(opt.strikePrice);
    if (pnl > 0) token.transfer(opt.owner, uint256(pnl) * opt.size / 1e18);
}
```

**Physical settlement:** Transfer the underlying token. More gas-intensive, exposes protocol to delivery risk.

---

## Stablecoin Design Patterns

### 8. CDP (Collateralized Debt Position) Mechanics

The MakerDAO/DAI model is the reference implementation:

**Minting:**
```
maxDebt = collateralValue * (1 / minimumCollateralRatio)
debt = userDefinedAmount <= maxDebt
```

**Typical parameters (DAI ETH vault):**
- Minimum collateral ratio: 150% (borrow $100 DAI → need $150 ETH)
- Liquidation ratio: 145% (liquidated if ratio drops below)
- Liquidation penalty: 13% (loses 13% of collateral to liquidators)
- Stability fee (interest): currently 5–15% APR

**CDP design decision: stability fee vs DSR:** The Dai Savings Rate (DSR) lets MakerDAO "pay" DAI holders interest to remove supply from circulation when supply exceeds demand. The stability fee must exceed the DSR to be sustainable.

### 9. Liquidation Auction Mechanisms

MakerDAO uses Dutch auctions for liquidations:

```
price(t) = startPrice * (1 - declineRate)^t
```

Price starts high and declines over time. Liquidators participate when price reaches their target discount.

**Advantage:** Maximizes recovery value vs instant liquidation.
**Risk:** In fast market crashes, Dutch auctions may not complete before price falls further ("price could decline faster than auction").

**Liquity's approach (Stability Pool):** Pre-deposited DAI-equivalent (LUSD) in stability pool absorbs liquidations immediately at oracle price. No auction required — simple, fast, eliminates auction risk.

### 10. Death Spiral Prevention

The critical failure mode for CDP stablecoins is a death spiral:
1. Collateral price drops → some CDPs undercollateralized
2. Liquidations sell collateral → further price drop
3. More liquidations → more selling → repeat

**MakerDAO mitigations:**
- Emergency Shutdown (nuclear option): freeze all CDPs at current oracle price, allow proportional redemption
- Multiple collateral types: diversification prevents single-asset cascade
- Global Debt Ceiling: hard cap on total DAI minted per collateral type

**Liquity's design:** 110% minimum collateral ratio (lower than MakerDAO's 150%) reduces liquidation impact because the collateral surplus per liquidation is smaller. Recovery Mode activates below system-wide 150% CR.

### 11. Algorithmic Stablecoins

The spectrum from fully-collateralized to purely algorithmic:

| Type | Example | Mechanism | Risk |
|---|---|---|---|
| 100% collateral | USDC | Each token backed by $1 fiat | Custodian/regulatory risk |
| CDP overcollateralized | DAI/LUSD | 150%+ crypto collateral | Liquidation cascade |
| Fractional reserve | Frax | Mixed: ~80% collateral + FRAX governance | Bank run risk |
| Algorithmic | UST (Terra) | Algorithmic expansion/contraction via LUNA | Death spiral (collapsed 2022) |

**Key lesson from UST collapse:**
- Pure algorithmic stablecoins rely on continuous confidence in the governance token
- If the governance token falls in value, the stablecoin loses its backing
- This creates reflexive instability: fear → governance token sell → stablecoin depeg → more fear
- **No purely algorithmic stablecoin has survived a major bear market**

### 12. Dual-Token Stablecoin (MoneyOnChain / fx Protocol)

Two-token system: stablecoin (stable) + risk-absorbing token (receives upside/downside of collateral):

```
stablecoinValue = fixed ($1)
riskTokenValue = (totalCollateral - stablecoinsOutstanding) / riskTokenSupply
```

**Stability mechanics:** When collateral drops in value, the risk token absorbs losses first. Stablecoin holders are protected until `totalCollateral < stablecoinsOutstanding`.

**Design constraint:** If collateral ratio drops too low (e.g., below 110%), emergency mechanisms (forced liquidations, new collateral requirements) must activate before the stablecoin loses its peg.

---

## Cross-Pattern Risks

### Derivatives + Stablecoin Interaction
Using a protocol's own stablecoin as collateral for perp positions creates reflexive risk:
- Perp positions lose → stablecoin collateral sold → stablecoin price drops → more positions liquidated
- Designed carefully, this can be stable (dYdX uses USDC); designed poorly, it amplifies volatility.

### Yield-Bearing Stablecoins (Ethena USDe)
Delta-neutral: hold ETH spot long + short ETH perp. Yield = funding rate on short position.

**Risk:** When funding rates go negative (bear market), the stablecoin generates negative yield. Ethena mitigates with an insurance fund; other implementations without reserves are at risk.

## Design Checklist

- [ ] Perps: Is funding rate calculated from robust index, not manipulable spot price?
- [ ] GMX-style GLP: Is there a price impact mechanism to prevent adverse selection?
- [ ] CDP: Is liquidation ratio above 100% with sufficient buffer for oracle latency?
- [ ] CDP: Is there a global debt ceiling per collateral type?
- [ ] Algorithmic stablecoin: Is there full collateral backing or a credible recovery mechanism?
- [ ] Dual-token: Does the risk token have sufficient supply to absorb realistic collateral drops?
- [ ] Options: Is IV recalibrated from external market data, not solely from on-chain prices?
- [ ] Yield-bearing stablecoin: Is negative yield scenario handled with an insurance reserve?