What Is Stablecoin?
A stablecoin is a cryptocurrency designed to maintain a stable value, typically pegged to the US dollar at $1.00. Stablecoins solve the volatility problem in crypto — they provide a stable unit of account for trading, a safe haven during downturns, and a medium of exchange for DeFi. Major stablecoins include USDT (Tether), USDC (Circle), DAI (MakerDAO), and USDS.
How Stablecoin Works
Stablecoins maintain their peg through different mechanisms: fiat-backed (USDT, USDC — each token is backed by $1 in reserves), crypto-backed (DAI — over-collateralized by crypto deposits), and algorithmic (various mechanisms to expand/contract supply based on demand). Each type carries different risks: fiat-backed relies on the custodian's solvency, crypto-backed can face cascading liquidations, and algorithmic can depeg catastrophically (Terra/UST).
Why It Matters for Traders
Stablecoins are the base currency of crypto trading. Most trading pairs are quoted against USDT or USDC. The total stablecoin supply is a macro indicator — growing stablecoin market cap signals fresh capital entering crypto, while shrinking supply signals outflows. Monitoring stablecoin flows to exchanges is one of the most direct indicators of imminent buying pressure.
How It Shows Up for Perps Traders
Even if you mainly trade CEX perps, stablecoin still matters when you hedge with spot, move collateral across chains, or compare DEX perps funding to CEX funding. Thin pool depth and oracle lag can widen the gap between the index you hedge and the book you trade.
Formula and Worked Example
Example numbers only (not a live quote).
Suppose you compare a spot bag and a short perp hedge. If the hedge notional is $5,000 and the spot bag drifts 2% while the hedge mark moves 1.2%, the residual basis is 0.8% of notional, or $40 on that $5,000 book. That gap is the cost of an imperfect hedge, separate from funding.
Common Mistakes
- Treating a single print of stablecoin as a trade signal without checking funding, open interest, and your liquidation price.
- Mixing venue conventions (coin-margined vs USDT-margined, cross vs isolated) and reading the wrong mark.
- Copying example numbers from a glossary into live size without checking the current book depth and fee schedule.
- Ignoring related terms that change the meaning of the print on a given day.
