DeFi on Bitsy Services Wiki

Blockchain

Mon, 01 Jan 0001 00:00:00 +0000

A blockchain is a distributed ledger made up of blocks – records containing a cryptographic hash of the previous block, a timestamp, and transaction data (typically structured as a Merkle tree). Because each block references the one before it, altering any historical record would require recomputing every subsequent block, making the ledger effectively immutable once written.

This property – append-only, tamper-evident history shared across many nodes – is what makes blockchains useful as trust infrastructure. No single party controls the ledger, and no single party needs to be trusted.

Cryptocurrency

Mon, 01 Jan 0001 00:00:00 +0000

Cryptocurrency is digital money secured by cryptography and running on a blockchain rather than through a bank or government. The blockchain acts as a public ledger: every transaction is recorded, verified by network participants (miners or validators), and made effectively permanent. No central authority issues the currency or processes transfers.

Bitcoin, launched in 2009, demonstrated that a decentralized payment network could work. Ethereum extended the idea by adding smart contracts, turning a blockchain into a programmable platform. Thousands of other cryptocurrencies exist, each with different design goals – some optimize for speed, some for privacy, some serve as governance tokens for specific protocols.

Cryptocurrency Gateway

Mon, 01 Jan 0001 00:00:00 +0000

A cryptocurrency gateway is a service that converts between fiat currency and cryptocurrency – commonly called an on-ramp (fiat to crypto) or off-ramp (crypto to fiat). These gateways are the entry and exit points between the traditional financial system and the blockchain economy.

Centralized gateways#

Most on/off-ramp activity today flows through centralized services that hold the necessary banking relationships and regulatory licenses.

Exchanges#

Centralized exchanges (Coinbase, Kraken, Binance) are the most common gateway. Users deposit fiat via bank transfer, wire, or card, buy crypto, and withdraw it to a self-custodial wallet. The reverse path – deposit crypto, sell for fiat, withdraw to a bank – serves as the off-ramp.

Smart Contract

Mon, 01 Jan 0001 00:00:00 +0000

A smart contract is a program deployed to a blockchain that executes automatically when its functions are called. Once deployed, the code is immutable (unless the contract uses an upgradeable proxy pattern) and its execution is deterministic — given the same state and inputs, every node on the network will produce the same result.

Smart contracts are the building blocks of DeFi. Every DEX, lending protocol, liquidity pool, and token is a smart contract or a set of interacting smart contracts.

Web3

Mon, 01 Jan 0001 00:00:00 +0000

Web3 is a shorthand for the idea of rebuilding internet services on decentralized infrastructure – primarily blockchains – so that users own their data and assets rather than renting access from platform companies. The term was coined by Gavin Wood, co-creator of Ethereum.

The pitch: Web 1.0 was read-only (static pages). Web 2.0 was read-write (user-generated content on centralized platforms like Facebook and YouTube). Web3 aims to be read-write-own, where the protocols themselves are open and the value accrues to participants rather than platform operators.

Decentralized Exchange

Mon, 01 Jan 0001 00:00:00 +0000

A decentralized exchange (DEX) is a marketplace for trading tokens that runs on-chain, without a central operator holding custody of user funds. Trades settle directly between the user’s wallet and a smart contract.

On a centralized exchange (CEX) like Coinbase or Binance, you deposit funds into the exchange’s custody, place orders against an order book the exchange operates, and trust the exchange to process withdrawals. A DEX replaces all of that with smart contracts: your tokens never leave your wallet until the moment the trade executes on-chain. There is no account to create, no KYC gate, and no withdrawal queue.

Decentralized Autonomous Organization (DAO)

Mon, 01 Jan 0001 00:00:00 +0000

A DAO is an organization governed by smart contracts on a blockchain rather than by a traditional management hierarchy. Rules are encoded in code, the treasury is managed on-chain, and decisions are made through proposals that members vote on. No single person or board has unilateral control.

DAOs matter because they offer a credibly neutral governance structure. Once the smart contracts are deployed, the rules apply equally to everyone – including the founders. This makes them a natural fit for managing DeFi protocols, shared treasuries, and any situation where participants need to coordinate without trusting a central operator.

Decentralized Application

Mon, 01 Jan 0001 00:00:00 +0000

A decentralized application (dApp) is software that runs its core logic on a blockchain through smart contracts rather than on servers controlled by a single operator. The frontend can be a normal website or mobile app, but the backend – the part that holds funds, enforces rules, and records state – lives on-chain and executes exactly as written.

The term covers a huge range: DEXs like Uniswap, lending protocols, prediction markets, games, DAOs, and more. What they share is that users interact with contracts directly from their own wallet, and no one can unilaterally change the rules once the contracts are deployed.

Finalized Smart Contract

Mon, 01 Jan 0001 00:00:00 +0000

A finalized smart contract is one that has been deployed to a blockchain with no mechanism for anyone – including its original developer – to modify its code or behavior. Once finalized, the contract runs exactly as written for as long as the blockchain exists.

This is the strongest form of the immutability property that makes smart contracts useful in the first place. A finalized contract cannot be censored, paused, upgraded, or tampered with by governments, corporations, or the developers who wrote it.

Automated Market Maker

Mon, 01 Jan 0001 00:00:00 +0000

An automated market maker (AMM) is a type of decentralized exchange that uses a mathematical formula – rather than an order book – to price trades. Traders swap against a liquidity pool instead of matching with a counterparty.

Traditional exchanges work by matching buyers and sellers: someone posts a bid, someone posts an ask, and the exchange matches them. This requires active market makers who continuously quote prices and enough participants on both sides to maintain a liquid book. On a blockchain, where every operation costs gas and blocks are seconds apart, maintaining an on-chain order book is expensive and slow. AMMs side-step the problem entirely. A smart contract holds reserves of two tokens, and a pricing function determines the exchange rate based on the ratio of those reserves. Anyone can trade at any time, and anyone can supply liquidity.

Liquidity Pool

Mon, 01 Jan 0001 00:00:00 +0000

A liquidity pool is a smart contract that holds reserves of two or more tokens and allows anyone to trade against those reserves according to a deterministic pricing function. Pools are the core primitive of AMM-based decentralized exchanges.

On a traditional exchange, liquidity comes from market makers who post bids and asks on an order book. On-chain, that model is impractical – gas costs and block times make continuous order management expensive. Liquidity pools solve this by letting anyone deposit tokens into a contract that automatically quotes prices using a formula like the constant product. Traders swap against the pool’s reserves; liquidity providers (LPs) earn a share of the fees.

Constant Product Formula

Mon, 01 Jan 0001 00:00:00 +0000

The constant product formula is the pricing rule at the heart of most AMM-based decentralized exchanges. It is elegant in its simplicity: a liquidity pool holds reserves of two tokens, and their product must remain constant through every trade.

x * y = k

where x and y are the reserve quantities and k is the invariant. Uniswap V2, SushiSwap, and most early AMMs use this formula. Understanding it is the key to understanding how on-chain trading, slippage, and impermanent loss work.

Constant Mean Formula

Mon, 01 Jan 0001 00:00:00 +0000

The constant mean formula is the pricing invariant behind Balancer’s weighted pools. Where the constant product formula constrains two-asset pools to a 50/50 split, the constant mean formula generalises to any number of assets with arbitrary weight ratios – 80/20, 60/20/20, or any combination that sums to 100%.

This makes it possible to build liquidity pools that behave like self-rebalancing index funds: LPs choose the asset mix they want exposure to, and the AMM maintains those proportions through trading fees rather than manual rebalancing.

Virtual Reserves

Mon, 01 Jan 0001 00:00:00 +0000

Virtual reserves are a mathematical abstraction used by AMMs to make a limited amount of real capital behave like a much larger liquidity pool. The idea is central to Uniswap V3’s concentrated liquidity and appears in various forms across other protocols.

The problem virtual reserves solve#

In a standard constant product pool, liquidity is spread across every price from zero to infinity. If a pool holds 10 ETH and 25,000 USDC, most of that capital sits at prices far from the current market and never facilitates a trade. The capital is real but idle.

Impermanent Loss

Mon, 01 Jan 0001 00:00:00 +0000

Impermanent loss (IL) is the difference in value between holding tokens in a liquidity pool and simply holding them in a wallet. It is the cost a liquidity provider (LP) pays for the pool’s automatic rebalancing — and it is the single most important risk to understand before depositing into an AMM.

Intuition#

An AMM pool always sells the token that is going up and buys the token that is going down. This is the mechanism that keeps the pool’s price in line with the market. The side effect is that an LP ends up with less of the appreciating token and more of the depreciating one — the opposite of what a holder would have.

Volatility

Mon, 01 Jan 0001 00:00:00 +0000

Volatility measures how much an asset’s price moves over a given period. In traditional finance it is a statistical concept – the annualised standard deviation of returns. In DeFi it is something you feel directly, because it drives impermanent loss, liquidation risk, option pricing, and the profitability of liquidity pool positions.

Cryptocurrency markets are structurally more volatile than most traditional asset classes. Tokens trade 24/7 on fragmented venues with thin order books, and prices respond sharply to regulatory news, exploit events, and social-media momentum. Understanding volatility is not optional for anyone deploying capital in DeFi.

Yield Farming

Mon, 01 Jan 0001 00:00:00 +0000

Yield farming is the practice of deploying crypto assets across DeFi protocols to earn returns – trading fees, interest, or token rewards. It is also called liquidity mining when the rewards come in the form of a protocol’s governance token.

The basic idea: protocols need liquidity to function. Decentralized exchanges need tokens in liquidity pools. Lending platforms need depositors. Rather than wait for capital to arrive organically, protocols offer incentives – often their own token – to attract it. Yield farmers chase those incentives, moving capital to wherever the returns are highest.

Nonce

Mon, 01 Jan 0001 00:00:00 +0000

In blockchain networks like Ethereum, a nonce is a per-account transaction counter that increments with each transaction sent. It serves two purposes: preventing replay attacks (the same signed transaction can’t be submitted twice) and ordering transactions from the same sender.

Staking

Mon, 01 Jan 0001 00:00:00 +0000

Staking is the act of locking cryptocurrency in a protocol to earn rewards. The term covers two distinct mechanisms: network staking, where locked tokens secure a blockchain’s consensus, and DeFi staking, where tokens are deposited into smart contracts to earn yield from protocol activity.

Both forms share the same core idea — you commit capital, accept illiquidity, and receive compensation for the service your capital provides.

Network staking (Proof of Stake)#

In a Proof-of-Stake (PoS) blockchain, validators lock tokens as collateral and are selected to propose and attest to blocks in proportion to their stake. Honest behaviour earns rewards (newly minted tokens plus transaction fees); dishonest behaviour triggers slashing, where some or all of the validator’s stake is destroyed.

Maximal Extractable Value (MEV)

Mon, 01 Jan 0001 00:00:00 +0000

Maximal Extractable Value (MEV) is the profit that can be captured by reordering, inserting, or censoring transactions within a block. It exists because the order in which transactions execute affects their outcomes — and the entity assembling a block gets to choose that order.

MEV matters because it is an invisible tax on every DEX trade, every lending-protocol liquidation, and every on-chain auction. Understanding it is essential to understanding why transactions sometimes fail, why gas spikes happen, and why DeFi protocols are designed the way they are.

Vanity Addresses and Salt Mining

Mon, 01 Jan 0001 00:00:00 +0000

A vanity address is an Ethereum address whose hex encoding contains a desired pattern — a leading run of zeros, a recognisable prefix like 0xC0FFEE…, or a trailing brand suffix. Because addresses are derived from a hash, you cannot ask for a specific address; you have to mine for one by trying inputs until the output matches your filter.

Two distinct flavours of mining show up in practice. The math is similar — Keccak-256 has no exploitable structure, so each candidate is an independent uniform draw — but the input you vary, the cost of a hit, and the security implications are very different.

Oracle Node

Mon, 01 Jan 0001 00:00:00 +0000

An oracle node is a piece of software that feeds external data into a blockchain. Smart contracts can only read on-chain state — they have no way to make HTTP requests, query databases, or observe the physical world. Oracles bridge this gap, and the nodes that run them are the infrastructure that makes data-dependent DeFi possible.

Without oracles, a lending protocol cannot know the price of collateral, an insurance contract cannot verify whether a flight was delayed, and a prediction market cannot settle bets.

Prediction Market

Mon, 01 Jan 0001 00:00:00 +0000

A prediction market is a platform where participants trade contracts whose payout depends on the outcome of a future event. The market price of each contract reflects the crowd’s estimated probability of that outcome. If a “Yes” share on “Will ETH be above $5,000 on December 31?” trades at $0.35, the market is pricing a 35% probability.

In DeFi, prediction markets run on smart contracts that handle market creation, trading, and settlement without intermediaries. The blockchain provides the settlement guarantee: once the outcome is determined, the contract pays winners automatically and irreversibly.

Prediction Market Event Time

Mon, 01 Jan 0001 00:00:00 +0000

Event time is the moment a prediction market determines its outcome. It governs when trading stops, when resolution begins, and when winning shares become redeemable. Getting event time right is one of the hardest design problems in on-chain prediction markets because it sits at the intersection of real-world timing, oracle reliability, and smart contract mechanics.

Resolution Lifecycle#

A typical on-chain prediction market moves through several time-bound phases:

Trading period – the market is open and participants buy and sell outcome shares. This phase ends at a predefined cutoff, which may or may not coincide with the real-world event.
Observation window – the event occurs (or fails to occur). The market waits for the outcome to become publicly verifiable.
Resolution – an oracle or designated resolver submits the outcome on-chain. The smart contract transitions the market to a settled state.
Redemption – holders of winning shares claim their payout.

The boundaries between these phases are defined by timestamps or block numbers encoded in the market’s smart contract.

DeFi and US Regulatory Restrictions

Mon, 01 Jan 0001 00:00:00 +0000

The US regulatory environment for DeFi is fragmented across multiple agencies, each with overlapping and sometimes conflicting jurisdictions. This page is a snapshot as of early 2026 – the landscape shifts frequently through enforcement actions, court rulings, and proposed legislation.

This is not legal advice. Anyone building or using DeFi protocols with US exposure should consult qualified legal counsel.

Key regulatory bodies#

SEC (Securities and Exchange Commission)#

The SEC regulates securities – investment contracts, stocks, bonds, and instruments that the Howey Test classifies as securities. The SEC’s position has been that many crypto tokens qualify as securities, particularly those sold in fundraising events where buyers expect profits from the efforts of others.

Groth16

Mon, 01 Jan 0001 00:00:00 +0000

Groth16 is a zero-knowledge proof system – specifically, a zk-SNARK (zero-knowledge Succinct Non-interactive ARgument of Knowledge). It allows a prover to convince a verifier that a computation was performed correctly, without revealing the computation’s inputs, and the verifier can check this in constant time regardless of how complex the original computation was.

Groth16 is the most widely deployed zk-SNARK in production blockchain systems. It powers the shielded transactions in Zcash, underpins several zk-rollup designs on Ethereum, and is used in cross-chain bridges, privacy protocols, and identity systems.

Micro-Transactions

Mon, 01 Jan 0001 00:00:00 +0000

A micro-transaction is a payment small enough that traditional payment infrastructure cannot process it economically – typically fractions of a cent to a few cents. On blockchains like Ethereum, transaction fees often exceed the value being transferred, making naive on-chain micro-transactions impractical. Solving this problem is one of the key challenges for pay-per-use business models, streaming payments, and machine-to-machine commerce.

Why Micro-Transactions Matter#

Many useful payment patterns only work when individual transfers can be vanishingly small:

Decentralized Keeper

Mon, 01 Jan 0001 00:00:00 +0000

A decentralized keeper is an autonomous agent – or a network of such agents – that monitors on-chain conditions and executes smart contract functions when those conditions are met. Keepers handle the “cron jobs” of DeFi: liquidations, oracle price updates, reward harvesting, limit-order execution, and any other task that a contract cannot trigger by itself because the EVM has no built-in scheduler.

Why Keepers Exist#

Smart contracts on Ethereum and other chains are reactive – they run only when an external account submits a transaction. Many protocol-critical actions (liquidating an under-collateralized loan, settling an expired option, compounding yield-farming rewards) must happen promptly, yet the contract cannot call itself. Keepers bridge this gap by watching for trigger conditions off-chain and submitting the necessary transaction when the time comes.

Smart Contracts in Real Estate

Mon, 01 Jan 0001 00:00:00 +0000

Real estate transactions are slow, expensive, and burdened with intermediaries – title companies, escrow agents, lawyers, and brokers each take a cut. Smart contracts on a blockchain can automate much of this pipeline, cutting costs and reducing the surface area for disputes.

Tokenized Ownership#

Tokenizing real estate means representing ownership shares as ERC-20 tokens on Ethereum or another programmable chain. This enables two models that are difficult or impossible with traditional title systems:

Fractional ownership. A property is divided into fungible tokens. Investors buy and sell fractions without the legal overhead of tenancy-in-common agreements. Liquidity improves because tokens can trade on secondary markets 24/7.
On-chain REITs. A real estate investment trust issues tokens backed by a portfolio of properties. Distributions flow automatically to token holders via smart contract logic, replacing the manual dividend process of traditional REITs.

In both models the token contract enforces cap-table accounting – who owns what percentage, transfer restrictions for regulatory compliance, and automated distribution of rental income or sale proceeds.

Staked Consensus Oracle

Mon, 01 Jan 0001 00:00:00 +0000

A staked consensus oracle is a design for decentralized data feeds in which oracle node operators lock up tokens as collateral and a consensus mechanism among stakers determines the value reported to a smart contract. Operators who report honestly earn rewards; operators who deviate from consensus are slashed – their staked collateral is partially or fully seized.

The core idea borrows from proof-of-stake consensus on blockchains: economic skin in the game aligns incentives without requiring a trusted third party.

Transfer on Join/Exit vs. Mint/Burn

Mon, 01 Jan 0001 00:00:00 +0000

When a user deposits assets into a liquidity pool or vault, the protocol needs a way to track their share. Two design patterns dominate: transfer on join/exit, which moves pre-existing tokens to represent membership, and mint/burn, which creates and destroys share tokens on the fly. The choice between them shapes a protocol’s accounting model, composability, and gas profile.

Transfer on Join/Exit#

In this pattern, the pool contract accepts a deposit and records the user’s share in internal storage – a mapping from address to balance. No new tokens are created. When the user withdraws, the contract updates the ledger and transfers the underlying assets back.

Collateralization Fee

Mon, 01 Jan 0001 00:00:00 +0000

A collateralization fee is the cost charged to minters when they create a cash-backed synthetic option (CBSO). It is calculated as a percentage of the staked collateral, prorated over the duration of the option, and serves as the primary revenue mechanism for the CBSO protocol.

How It Works#

When a minter deposits collateral into the CBSO smart contract to mint new option tokens, the contract charges a collateralization fee on top of the collateral amount. The fee is expressed as an annual percentage rate applied to the collateral value, prorated to the option’s time to expiration.

Fee Box

Mon, 01 Jan 0001 00:00:00 +0000

The Fee Box is a smart contract in the CBSO system that acts as the central collection point for collateralization fees. After all options for a given expiry are settled, the Option Settler transfers accumulated fees to the Fee Box, where they are held until distributed to protocol stakeholders.

Role in the CBSO System#

During the lifetime of a CBSO, collateralization fees are held within the individual option contracts. The fees do not move until settlement is complete. Once the Option Settler has processed all options for an expiry, it calls collectFees() on the Fee Box, transferring the total accumulated fees in a single operation.

Liquidity Floor

Mon, 01 Jan 0001 00:00:00 +0000

A liquidity floor is a price below which a token cannot trade because there is no liquidity there to sell into. The floor is not defended — there is no buyback, no peg keeper, no treasury bid. It is enforced by the absence of any position beneath it. A sell order has nowhere to go, so price stops.

Floor by defense vs. floor by absence#

There are two ways to stop a price from falling:

Oracle-Free Pricing

Mon, 01 Jan 0001 00:00:00 +0000

Oracle-free pricing means a contract derives the price of an asset entirely from on-chain liquidity geometry — the shape and position of an AMM position — rather than reading an external price feed. There is no number to fetch and trust. The position is the price.

What an oracle costs you#

A price oracle imports an external fact onto the chain: “ETH is worth 3,000 USDC.” Anything that depends on that import inherits its failure modes:

Locked Liquidity

Mon, 01 Jan 0001 00:00:00 +0000

Locked liquidity is an AMM position whose principal can never be withdrawn — not by its creator, not by anyone. It is the difference between “the team promises not to pull the pool” and “the pull function does not exist.” A liquidity floor or a peg is only as credible as the guarantee that the backing stays put; locked liquidity is that guarantee made structural.

Three ways to lock#

Time-lock. A locker contract holds the position and releases it after a deadline. Common for launches; only as good as “until the timer ends,” and the cliff is a known risk date.
Burn. Send the LP token (or V2 LP shares) to a dead address. Irreversible, but crude — you also burn the ability to ever collect fees, and V3/V4 positions are NFTs with accrued fees, so burning is lossy.
No withdrawal path. Own the position via a contract that simply never implements decrease-liquidity. Principal is unreachable because no code can reach it; fees remain collectable. This is the strongest and most precise form.

Fee-only ownership#

The refined pattern separates two rights that LP ownership normally bundles:

Full-Reserve Backing

Mon, 01 Jan 0001 00:00:00 +0000

Full-reserve backing means every unit of an issued instrument is backed one-for-one by the real underlying asset held in reserve — not by different collateral, not fractionally, not by an algorithm. The reserve is the same asset the instrument represents. It is the oldest idea in monetary engineering, and it predates DeFi by centuries.

Full reserve vs. the alternatives#

Model	Backing	Fails when
Full reserve	100% of the same asset	reserve custody is compromised
Fractional	Part reserve, part assumption that not everyone redeems at once	redemptions exceed the fraction (a run)
Over-collateralized synthetic	A different asset worth >100%, oracle-priced	the collateral crashes or the oracle lies
Algorithmic	A mechanism and a reflexive belief	belief evaporates

Full reserve is the only model with no insolvency mode of its own. Its single failure surface is custody of the reserve. Everything else trades that simplicity for capital efficiency or yield — and inherits a run, a liquidation cascade, or a death spiral in exchange.

Permissionless Token Factory

Mon, 01 Jan 0001 00:00:00 +0000

A permissionless token factory is a contract anyone can call to deploy a new token — or a new token and its market — with no gatekeeper, no allowlist, no listing fee, and no privileged operator afterward. It is the difference between “apply to launch a token” and “call a function.”

The factory + clones pattern#

Deploying a fresh contract per token is expensive. The standard construction is a factory that stamps out minimal-proxy clones (EIP-1167): every token is a tiny proxy delegating to one shared implementation. Deployment cost collapses to roughly the cost of the proxy. Pair this with CREATE2 and each clone’s address is deterministic — a pure function of the factory, the implementation, and the salt — so the address is known before deployment and is identical across chains.

Interbox

Mon, 01 Jan 0001 00:00:00 +0000

Interbox is a proposed fiat-to-crypto transfer service that lets users move funds from a U.S. bank account to a self-custodied crypto wallet without creating an account on an exchange or repeating KYC checks. It relies on the KYC already performed by the user’s bank, cryptographically linking the bank account to the wallet so that Interbox can verify ownership without collecting sensitive identity documents.

The problem it solves#

Buying crypto into a self-custodied wallet typically means signing up for an exchange, passing KYC (government ID, selfie, sometimes biometrics), waiting for verification, buying the asset, and then withdrawing to your wallet. Each exchange requires its own KYC, multiplying data exposure. Transaction holds of up to seven days are common.

Par Token

Mon, 01 Jan 0001 00:00:00 +0000

A par token is a token whose price against one specific reference asset is structurally clamped to a hard, narrow band starting at parity — acquirable at a known maximum premium, exitable at no worse than par — backed at least 1:1 by the real reference asset, with no oracle, no redemption function, and no governance, permissionlessly instantiable for any ERC-20.

It is not a new primitive. It is a specific composition of documented ones, and the value is in the conjunction.

Currency

Mon, 01 Jan 0001 00:00:00 +0000

Currency is any widely accepted medium of exchange, unit of account, and store of value. It is the foundational abstraction that makes trade possible – without it, every transaction requires a direct barter of goods or services.

Forms of currency#

Commodity money#

The earliest currencies were physical commodities with intrinsic value – gold, silver, salt, cattle. These worked because they were scarce, durable, and widely recognized, but they were heavy to transport and impractical to divide precisely.