Lately, I’ve been thinking that the topic of digital currencies seems to be getting more and more attention. To put it in perspective, there are now more than 20,000 cryptocurrencies in circulation, daily trading volume is above hundreds of billions of dollars, and there are over 300 million users worldwide. This scale is definitely not small.

First, let’s talk about what a digital currency is. Usually, when we say “digital currency,” we actually mean decentralized cryptocurrencies—operating based on cryptography and P2P technology, with no reliance on any physical assets. This is quite different from traditional electronic payment systems (such as PayPal), which are still centralized.

If we classify them by market capitalization, digital currencies can roughly be divided into three tiers. Large-cap coins generally have relatively lower risk, deeper liquidity, and are best suited for beginners. Mid-cap tokens are more volatile, but they also have stronger growth potential. Small-cap tokens require extra caution: liquidity is poor, they can easily surge or plunge sharply, and the risk is particularly high.

As for how to choose, my advice to beginners is to prioritize mainstream coins that rank near the top by market cap. Bitcoin (BTC) is currently priced at around $77.63K, with a market cap of $1.55T, making it the most robust option for getting started. As the “gold standard” of cryptocurrencies, it has a low barrier to understanding, the strongest liquidity, and has already been included on the balance sheets of major companies like Tesla and MicroStrategy. Moreover, based on the PoW consensus mechanism and a decentralized network of nodes, its security has been tested over time and is basically impossible to tamper with.

Ethereum (ETH) is currently $2.12K, with a market cap of $255.76B, ranking second. Its advantage lies in ecosystem support—most DeFi, NFT, and chain gaming projects are built on Ethereum, which means there is real demand for practical applications. After switching to PoS, scalability improves and energy consumption decreases, and its long-term potential is widely viewed positively.

XRP (Ripple) is currently priced at $1.36, with a market cap of $84.25B. This coin has a clear use case: it focuses on cross-border payments for financial institutions and can complete low-cost international remittances in 3–5 seconds. However, note that XRP has a relatively high degree of centralization, and legal risks still exist—so it’s recommended to allocate only a small position.

Coins issued by a major exchange (current price: $662.60, market cap: $89.31B) are also worth paying attention to. It’s not just an investment asset—it’s also an “access pass” within its ecosystem. Using it to pay transaction fees can get you discounts. In addition, the exchange buys back and burns this coin every quarter using its profits, which may help drive the price up over the long term.

Stablecoins (USDT currently $1.00, USDC currently $1.00) are something every beginner must understand. They are pegged 1:1 to the US dollar, with zero volatility, making them especially suitable for practicing trading operations or temporarily hedging. In bear markets, many people convert their funds into stablecoins to preserve value.

When it comes to the pros and cons of digital currencies, I think we should be objective. On the advantages side, the issuance rules are effectively “hard-coded” at the code level, which prevents over-issuance and excessive dilution. Transactions are secured and made transparent through a consensus mechanism, and the costs are far lower than traditional channels. Also, they have two-way transfer liquidity, making cross-border transfers fast and cheap.

The disadvantages also need to be acknowledged. Price volatility is far too intense, and there’s a lack of a stable benchmark for value—any sudden factor can trigger huge fluctuations. There are also storage security concerns: if you forget your wallet password, your funds are lost permanently, which is disastrous for users.

If you want to invest in digital currencies, there are mainly a few ways to do it. The most common is buying through mainstream exchanges: after completing identity verification, you can deposit fiat directly. But when choosing an exchange, you must select one that is compliant and reputable, because many exchanges still operate in regulatory gray areas. Decentralized exchanges (DEXs) are also an option, but you need to manage your own wallet, and the risks are borne by you.

There are also derivatives trading methods such as contracts for difference. You don’t need to actually hold digital currencies—you’re simply predicting whether the price will rise or fall. Many broker platforms adopt a zero-commission model, which is more friendly to traders with smaller amounts of capital. And since you don’t have to manage wallets and private keys, the funds are kept in segregated accounts, which can feel safer than using an exchange.

Finally, one last piece of advice for beginners: when investing in digital currencies, you must avoid two pitfalls. First, don’t touch low-market-cap altcoins, especially those ranked after the top 100—these tend to have high volatility and high risk. Second, don’t choose projects that don’t have a whitepaper, with an anonymous team, or are based purely on hype—most of these (9 out of 10 and a half) are just there to cut retail investors’ “grass.”

Overall, the digital currency market is being recognized more and more, and countries around the world are planning their own digital currencies. In the future, this field should attract even more new users. If you’re interested, you can start by getting hands-on with stablecoins, gradually learn about the market, and then consider allocating to mainstream coins.