Cryptocurrencies trade around the clock, swing wildly and attract both serious institutions and outright scams. Whatever your view, crypto is now part of the market landscape, with exchange-traded products in several countries and live prices on every financial dashboard. This guide explains the essentials in a balanced way.
What is a blockchain?
A blockchain is a shared ledger maintained by a network of computers rather than a single institution. Transactions are grouped into blocks, cryptographically linked to previous blocks, and validated by the network according to fixed rules. Once confirmed, records are extremely difficult to alter. This lets people transfer value directly without a bank in the middle.
Bitcoin
Bitcoin, launched in 2009, was the first cryptocurrency. Its supply is capped at 21 million coins, with new issuance cut in half roughly every four years in an event called the “halving”. Supporters see it as digital gold: scarce, portable and independent of any government. Critics point to its volatility, energy use under its proof-of-work system, and lack of cash flows to value. It remains by far the largest crypto asset by market value.
Ethereum and smart-contract platforms
Ethereum introduced programmable “smart contracts”: code that runs on the blockchain automatically. These power decentralised finance (DeFi) applications for lending and trading, tokens, NFTs and more. Ether (ETH) pays for computation on the network. Since 2022 Ethereum has used proof-of-stake, where validators lock up coins instead of using mining hardware. Competing platforms include Solana, Avalanche, Cardano and others.
Altcoins and tokens
“Altcoins” are all cryptocurrencies other than Bitcoin, numbering in the thousands. Some fund real networks with users; many have little purpose beyond speculation. Smaller coins can rise or fall 50% in days, are easier to manipulate and frequently disappear. Treat the long tail of tokens with extreme caution.
Stablecoins
Stablecoins aim to hold a constant value, usually $1, by holding reserves such as cash and short-term government debt. They are the main trading currency on crypto exchanges and are increasingly used for payments. Their safety depends entirely on the quality and transparency of their reserves and on regulation; algorithmic stablecoins without solid reserves have failed spectacularly.
How crypto is traded
- Centralised exchanges work like brokers: easy to use, but you trust them with your coins. Several large exchanges have collapsed, so regulation and reputation matter.
- Decentralised exchanges (DEXs) let you trade directly from your own wallet via smart contracts, with different risks such as contract bugs.
- Exchange-traded products in some markets give price exposure through a regular brokerage account, without handling coins yourself.
Custody: “not your keys, not your coins”
Owning crypto means controlling a private key. On an exchange, the exchange holds it. In a self-custody wallet, you do, and if you lose your recovery phrase, nobody can restore your funds. Hardware wallets keep keys offline for security. Never share a recovery phrase; no legitimate support agent will ever ask for it.
Volatility and correlation
Bitcoin has experienced multiple drawdowns of 70% or more from its peaks, and smaller coins far worse. Crypto often trades as a high-risk asset: it can fall alongside technology stocks when liquidity tightens and interest rates rise. View the whole market at a glance on our crypto heatmap.
Key risks checklist
- Price risk: extreme swings; size positions accordingly (see risk management).
- Platform risk: exchange failures, hacks and frozen withdrawals.
- Scams: fake giveaways, pump-and-dumps, romance and “guaranteed yield” schemes.
- Regulatory risk: rules differ by country and continue to evolve.
- Tax complexity: many jurisdictions tax each disposal, including crypto-to-crypto swaps.
If you choose to participate
- Only invest money you can afford to lose entirely.
- Keep crypto a small slice of a diversified portfolio.
- Prefer established assets and regulated platforms.
- Use strong, unique passwords and two-factor authentication; consider a hardware wallet for larger amounts.
- Be sceptical of anyone promising returns.
Crypto assets are highly speculative and may not be regulated in your jurisdiction. Educational content only, not investment advice.