Learning Objectives:

  • Understand stablecoin types and mechanics

  • Master algorithmic stablecoin economics

  • Learn about stablecoin risks and failures


5.4.1: What are Stablecoins?

Definition and Purpose:

Stablecoins are cryptocurrencies designed to maintain a stable value relative to a reference asset (usually USD).

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Stablecoin Use Cases:

1. Trading:
   - Trading pairs
   - Settlement
   - Price stability

2. Payments:
   - Remittances
   - E-commerce
   - Peer-to-peer

3. DeFi:
   - Lending/Borrowing
   - Yield farming
   - Collateral

4. Store of Value:
   - Hedging volatility
   - Savings
   - Income generation

5.4.2: Stablecoin Types

Type 1: Fiat-Backed Centralized

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Fiat-Backed Stablecoins:

USDC (Circle):
┌─────────────────────────────────────────────────────────────────────┐
│  Asset: USD (held in banks)                                      │
│  Issuer: Circle                                                 │
│  Regulation: US regulated                                       │
│  Transparency: Monthly attestations                             │
│                                                                   │
│  Example: 1 USDC = 1 USD (backed by USD reserves)               │
└─────────────────────────────────────────────────────────────────────┘

USDT (Tether):
┌─────────────────────────────────────────────────────────────────────┐
│  Asset: USD + cash equivalents                                   │
│  Issuer: Tether Limited                                         │
│  Regulation: Limited                                            │
│  Transparency: Disputed                                         │
│                                                                   │
│  Example: 1 USDT ≈ 1 USD (partially backed)                    │
└─────────────────────────────────────────────────────────────────────┘

Type 2: Crypto-Backed Overcollateralized

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Crypto-Backed Stablecoins:

DAI (MakerDAO):
┌─────────────────────────────────────────────────────────────────────┐
│  Collateral: ETH, WBTC, USDC                                    │
│  Mechanism: Overcollateralized Vaults                           │
│  Stability: Collateralization ratio >150%                      │
│                                                                   │
│  Example: 1 DAI ≈ 1 USD (backed by $1.50 worth of ETH)        │
└─────────────────────────────────────────────────────────────────────┘

Type 3: Algorithmic (No Collateral)

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Algorithmic Stablecoins:

TerraUSD (UST) - Failed:
┌─────────────────────────────────────────────────────────────────────┐
│  Mechanism: Algorithmic expansion/contraction                    │
│  Collateral: No underlying collateral                            │
│  Stability: Secondary token (LUNA)                              │
│                                                                   │
│  Problem: Death spiral when confidence breaks                   │
└─────────────────────────────────────────────────────────────────────┘

5.4.3: DAI – The Decentralized Stablecoin

MakerDAO Architecture:

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MakerDAO System:

┌─────────────────────────────────────────────────────────────────────┐
│                    MakerDAO Architecture                           │
│                                                                   │
│  Vaults:                                                          │
│  ┌─────────────────────────────────────────────────────────────┐   │
│  │  Collateral: ETH, WBTC, USDC                              │   │
│  │  Min Collateral Ratio: 150-170%                          │   │
│  │  Mint: DAI against collateral                              │   │
│  └─────────────────────────────────────────────────────────────┘   │
│                              │                                    │
│  Stability Fee:                                                   │
│  ┌─────────────────────────────────────────────────────────────┐   │
│  │  Interest rate on DAI loans                               │   │
│  │  Adjusted by governance                                   │   │
│  │  Currently: 5-10%                                         │   │
│  └─────────────────────────────────────────────────────────────┘   │
│                              │                                    │
│  DAI Savings Rate:                                               │
│  ┌─────────────────────────────────────────────────────────────┐   │
│  │  Interest on DAI holdings                                 │   │
│  │  Paid from stability fees                                 │   │
│  │  Current: 3-8%                                            │   │
│  └─────────────────────────────────────────────────────────────┘   │
└─────────────────────────────────────────────────────────────────────┘

5.4.4: Algorithmic Stablecoin Economics

The Death Spiral:

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Algorithmic Death Spiral:

1. Confidence Weakens:
   ┌─────────────────────────────────────────────────────────────┐
   │  Stablecoin de-pegs below $1                             │   │
   └─────────────────────────────────────────────────────────────┘
                            │
                            ▼
   ┌─────────────────────────────────────────────────────────────┐
   │  2. Sell Pressure:                                         │   │
   │  • Users sell stablecoins                                 │   │
   │  • Price drops further                                    │   │
   └─────────────────────────────────────────────────────────────┘
                            │
                            ▼
   ┌─────────────────────────────────────────────────────────────┐
   │  3. Algorithm Responds:                                    │   │
   │  • Mints more governance tokens                          │   │
   │  • Sells for stablecoins                                 │   │
   └─────────────────────────────────────────────────────────────┘
                            │
                            ▼
   ┌─────────────────────────────────────────────────────────────┐
   │  4. Death Spiral:                                          │   │
   │  • Governance token crashes                                │   │
   │  • Algorithm cannot recover                                │   │
   │  • Stablecoin becomes worthless                          │   │
   └─────────────────────────────────────────────────────────────┘

5.4.5: Stablecoin Risks

 
 
Risk Description Example
Collateral Risk Collateral value drops DAI 2020 crash
Algorithmic Failure Death spiral TerraUSD
Regulatory Risk Legal issues USDC blacklisting
Banking Risk Bank failures Silicon Valley Bank
De-Peg Risk Price deviation USDC de-peg 2023

5.4.6: Stablecoin Market Overview

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Stablecoin Market (2024):

Top Stablecoins:
1. USDT: ~$100B (Tether)
2. USDC: ~$30B (Circle)
3. DAI: ~$5B (MakerDAO)
4. USDe: ~$2B (Ethena)

Total Stablecoin Market: ~$150B

Growth:
- 2020: $20B
- 2021: $150B
- 2022: $200B
- 2023: $140B
- 2024: $150B+