Bitcoin Terms Beginning with M

M-of-N describes a multisig setup in which N public keys are given joint custody of bitcoin, and M signatures from any of those N keys are required in order to spend the bitcoin.

Mainnet is the term for the real Bitcoin blockchain and network, and is used in contrast with testnet, signet, and regtest networks. Mainnet coins (BTC) have monetary value and are not used for testing.

A maker order is an order that does not execute immediately. Maker orders create the liquidity on a market that allows taker orders to execute.

Transaction malleability is the ability of a transaction to have multiple valid IDs (txids). Malleability occurs when a part of a transaction can change after the transaction has been signed.

Margin trading occurs when a trader borrows money to execute a trade. Margin trading makes use of leverage to purchase or sell more assets than a trader would otherwise have access to.

Market capitalization is a measure of how much the total supply of an asset is worth. Market capitalization is found by multiplying the price per unit of the asset by the total number of units in circulation.

Market depth refers to the quantity of an asset that is available to trade on a market. Higher depth results in more efficient trading.

Market impact refers to the effect a trader has on the market when they trade an asset. Market impact will usually hurt the trader, resulting in slippage.

A market maker is willing to buy or sell large quantities of an asset simultaneously. This adds significant liquidity to the market.

A market order is an order to buy or sell an asset immediately. This order does not specify a price, but will be executed at the market price at that time.

The maturity date of a financial instrument is the point at which that instrument is redeemable for face value, and no longer accrues interest payments.

A medium of exchange is a type of good or currency that facilitates the exchange of other goods and services within an economy by serving as a common denominator of value for the goods exchanged.

The mempool (memory pool) is a smaller database of unconfirmed (pending) transactions which every node keeps. All transactions in the mempool are pending, and should not be trusted until they are included in a block.

A mempool explorer is a software application that serves useful information about the current and past states of the mempool, including fee rates, transaction volume, and more.

A Merkelized Alternative Script Tree (MAST) is a proposal to encapsulate an arbitrary number of different scripts in a Bitcoin address.

The Merkle root is the final node in a Merkle tree. It is a hash which includes the hashes of all transactions in a block.

A Merkle tree is a data structure which stores all transactions in a given block. The Merkle tree's root is placed in the block header as a summary of all transactions.

A Merkle-Sum tree is a type of Merkle tree that makes it efficient to verify that there is no change in the cumulative value or distribution of the leaves of a Merkle tree.

Metcalfe’s law states that the value of a network is proportional to the square of the number of nodes, or members, in the network.

A Miner-Activated Soft Fork (MASF) is a soft fork which is activated by miners who begin mining blocks under the updated ruleset.

Mining is the process of building the blockchain by adding new blocks one at a time. Most of mining involves finding a valid Proof-of-Work, which is an energy-intensive guessing game.

A mining pool is a cooperative setup which allows smaller miners to pool their hashrate and thereby smooth their revenues. When a member of a pool finds a valid block, they split the rewards with the rest of the pool based on each member's hashrate contribution.

A mixing service accepts bitcoin deposits and sends different pieces of bitcoin back to the user in the same amount. When done properly, this effectively obscures ownership of the bitcoin and allows users to privatize their bitcoin.

A mnemonic phrase is a list of 12-24 words used to back up a wallet. These words can be decoded to yield the seed of a wallet, which generates public and private keys for the wallet.

The monetary base of a currency is a measure of how much of the currency is in circulation. Increases in the monetary base tend to cause inflation.

The money multiplier is a ratio that measures the potential increase in the money supply for a given cash injection. The money multiplier is a function of the proportion of deposits that a bank keeps in reserve, known as their reserve ratio.

The money supply is a measure of all the money that is available in an economy. Money can be classified in several ways, with each one resulting in a different money supply.

Moore’s law observes that the number of transistors in electronic circuits doubles about every two years. This roughly translates to a doubling of processing power in the same timespan.

A multipath payment is a type of Lightning payment which is executed as an atomic set of smaller payments. These smaller payments are more reliable and easier to execute.

Bitcoin can be sent to an address such that spending that bitcoin requires multiple signatures from different private keys. This setup allows joint custody of funds, and can be as simple or as complex as needed.

MuSig is a protocol for creating Taproot multisig public keys and signatures. MuSig makes use of Schnorr signature and public key aggregation