Cryptocurrency Cheat Sheet 2026

The 30 highest-yield Cryptocurrency facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What was the name of the well-known Japanese Bitcoin exchange that went bankrupt in 2014? → Mt. Gox
2. On the CoinDesk Bitcoin Price Index, what was the highest Bitcoin price ever? → $1,165
3. What is a flash loan in DeFi? → An uncollateralized loan that must be borrowed and repaid within a single transaction
4. What is TVL (Total Value Locked) a measure of in DeFi? → The total dollar value of assets deposited in a DeFi protocol
5. What is the 'avalanche effect' in the context of cryptographic hashing? → A small change in the input data results in a completely different hash output.
6. Which of the following is the most common method of keeping bitcoins? → Wallet
7. What does the term 'slippage' refer to in DEX trading? → The difference between the expected and actual execution price of a trade
8. Is there a limit to how many bitcoins may be created? → 21 million
9. What is the purpose of an oracle in smart contracts? → To provide smart contracts with real-world external data they cannot access natively
10. What does it mean for a smart contract to be 'immutable'? → Once deployed, the contract code cannot be changed on the blockchain
11. Which Ethereum token standard is most commonly used for NFTs? → ERC-721
12. What is 'gas' in the context of Ethereum smart contracts? → A unit measuring computational effort required to execute operations on Ethereum
13. What is the primary advantage of Elliptic Curve Cryptography (ECC) over RSA in the context of cryptocurrencies like Bitcoin? → ECC provides equivalent security with smaller key sizes.
14. Which of the following is NOT a fundamental property of a cryptographic hash function used in blockchain technology? → Reversibility
15. What is the meaning of UTXO? → Unspent Transaction Output
16. What was the name of the first academic study that described bitcoin as it is now known? → The Bitcoin Whitepaper
17. When did the Bitcoin Network begin? → January 2009
18. What is an Automated Market Maker (AMM) in DeFi? → A protocol that uses liquidity pools and algorithms to price assets
19. What is the Ethereum Virtual Machine (EVM)? → The decentralized computation engine that executes smart contracts on Ethereum
20. Is it possible to program a blockchain to automatically record transactions? → B) Yes
21. In DeFi lending protocols like Aave or Compound, what is over-collateralization? → Providing collateral worth more than the loan amount
22. What is a LiteClient, and how does it work? → Allows you to interact with the blockchain without downloading the whole blockchain
23. What is 'wash trading' in NFT markets? → A seller buying their own NFTs repeatedly to artificially inflate volume and price
24. Which programming language is most widely used to write Ethereum smart contracts? → Solidity
25. What is 'provenance' in the context of NFTs? → The verifiable ownership and transaction history of an NFT recorded on the blockchain
26. What is the purpose of a wrapped token (e.g., WBTC)? → To represent a non-native asset on a different blockchain
27. What is a dApp (decentralized application)? → An application that runs on a decentralized blockchain network using smart contracts
28. In a Delegated Proof-of-Stake (DPoS) system, how are the entities that create and validate new blocks, often called 'witnesses' or 'delegates', chosen? → They are elected by the token-holding community through a continuous voting process.
29. True or false: Blockchain and Bitcoin are the same thing. → A) False
30. What does NFT stand for? → Non-Fungible Token