A DEX price is not quoted by anyone; it is computed by a formula from two pool balances. Nearly everything else follows from that, and from the fact that you keep your own keys.
Direct answer
A decentralized exchange lets people trade directly from their own wallets, with trades settled by smart contracts rather than by a company holding customer funds. Most price trades with an automated market maker — a formula over pool reserves — rather than an order book. Nobody takes custody, nobody checks the tokens, and nobody can reverse a mistake.
Start here
| If you want to… | Read |
|---|---|
| Understand the pricing mechanism | How Decentralized Exchanges Work |
| Know what a DEX is, honestly | What Is a Decentralized Exchange |
| Decide between DEX and exchange | DEX vs Centralized Exchange |
| Know what you are signing | Wallet-Based Trading Explained |
| Trade without losing money to avoidable mistakes | How to Use a DEX Safely |
Three things worth knowing before you trade
1. Your price comes from a formula, not a counterparty
The common design is the constant product rule, x × y = k. A pool holds two tokens and every trade must leave their product unchanged, so your price is computed from the reserves.
The consequence people miss: your execution impact is simply your spend divided by the pool's reserve of what you are spending. In a pool holding 1,000 ETH and 2,000,000 USDC, a 10,000 USDC buy costs about 0.5% — a 1,000,000 USDC buy costs 50%. The trade still succeeds at either size. That is the trap: an order book runs out and tells you, a curve just gets worse quietly.
The full arithmetic is worked step by step in how decentralized exchanges work.
2. Approvals, not keys, are how wallets get drained
Trading from a wallet means granting contracts permission to move your tokens. That permission persists until revoked, is commonly requested as unlimited, and does not look like giving away money.
A permit signature grants identical authority with no gas cost, which makes it feel inconsequential. It is not. A gasless signature is not a harmless signature.
3. Nobody vetted the token
Listing is permissionless. Anyone can deploy a contract using an established project's name and ticker and create a pool for it — so the verification a centralized exchange performs transfers entirely to you.
Search by contract address, not by name, taken from a source the project controls.
What a DEX removes, and what it adds
| Risk removed | Risk introduced |
|---|---|
| Operator insolvency or hack | Smart contract bugs and exploits |
| Account freezing | Irreversible mistakes, no support |
| Withdrawal restrictions | Gas costs and failed transactions |
| — | Malicious approvals draining a wallet |
| — | Impersonator tokens and honeypots |
| — | MEV extraction from your pending transaction |
Neither model is categorically safer. They relocate risk — one to an operator, one to you and the contract code. See DEX vs centralized exchange.
Where CoinDock sits
CoinDock is a centralized, order-book exchange: custodial holdings, price-time priority matching, identity verification, and reviewed listings.
We publish DEX education because the mechanics matter wherever you trade, and because the comparison deserves an honest treatment rather than a sales pitch — a reader who picks the wrong model for their situation loses money either way.
Guides in this pillar
Concepts
- What Is a Decentralized Exchange
- DEX vs Centralized Exchange
- Wallet-Based Trading Explained
- Trading With USDT
- How Decentralized Exchanges Work
How-to
- How to Use a DEX Safely
- How to Connect a Crypto Wallet
- How to Place a DEX Order
- How to Swap Tokens on a DEX
- How to Spot Common DEX Risks
Questions
Related pillars
- Liquidity — depth and slippage on order books.
- Security — contract verification and wallet safety.
- Listings — what a reviewed listing involves.
Educational content. Not financial, investment, or legal advice. Cryptocurrency trading carries risk of total loss.
Core Topics
What Is a Decentralized Exchange?
A DEX settles trades through smart contracts while you keep custody. What that removes is clear. What it replaces those risks with is discussed less.
DEX vs Centralized Exchange
Neither model is safer. They relocate risk — one to an operator, one to you and the contract code.
Wallet-Based Trading Explained
Trading from a wallet means authorising specific actions. Knowing what each signature grants is the difference between a trade and a drained wallet.
Trading With USDT
Quoting in a stablecoin is an exposure, not a neutral resting place. Which exposure depends on how the coin is backed.
How Decentralized Exchanges Work
Most explanations stop at 'smart contracts handle it'. This one shows the formula that sets your price and walks the arithmetic.
How-To Guides
Frequently Asked Questions
What is a decentralized exchange?
A DEX is a trading venue where users keep custody of their funds and trade directly from wallets via smart contracts.
How is a DEX different from a CEX?
A DEX does not custody user funds; a CEX holds funds on behalf of users and acts as a central counterparty.
Why trade against USDT?
USDT provides relatively stable pricing, which simplifies valuation, accounting, and cross-pair comparisons.
Are DEX trades reversible?
Most on-chain DEX transactions are final once confirmed; understand a trade before signing it.
What is an AMM?
An Automated Market Maker uses liquidity pools and pricing formulas instead of an order book to quote trades.
Do I need a wallet to use a DEX?
Yes — most DEX activity requires a self-custodial wallet that can sign transactions.
What gas costs apply on a DEX?
Trades pay chain gas fees in addition to any protocol fees; gas varies by chain and network load.
Can DEXes get hacked?
Smart contracts can have bugs. Always check audits and avoid concentrating funds in untested venues.
Glossary
AMM
Automated Market Maker — uses liquidity pools and a pricing curve to quote trades.
Custody
Who holds the private keys that control an asset.
DEX
A decentralized exchange where users keep custody of their assets.
Front-Running
Exploiting pending transactions in the mempool to capture price.
Gas Fee
A blockchain network fee paid to validators for executing a transaction.
Liquidity Pool
A pool of tokens contributed by liquidity providers used to back AMM trades.
MEV
Maximal Extractable Value — profits validators can capture by re-ordering transactions.
Order Book
A list of resting bids and asks at price levels.
Self-Custody
Holding your own keys instead of trusting a third party.
Slippage Tolerance
The maximum allowed price drift on a DEX trade before it reverts.
Swap
A direct exchange of one token for another on a DEX.
Wallet
Software or hardware that stores private keys and signs transactions.
Learn How CoinDock Works
Learn how decentralized exchanges work, how wallet-based trading differs from centralized custody, and how CoinDock fits into the modern crypto landscape.
Learn How CoinDock Works