The role of Ethereum smart contract is to realize decentralized, automated and transparent protocol execution. Its core functions include: 1. As the core logic layer of DApp, it supports token issuance, DeFi, NFT and other functions; 2. Automatically execute contracts through code to reduce the risks of human intervention and fraud; 3. Build a DeFi ecosystem so that users can directly conduct financial operations such as lending and transactions; 4. Create and manage digital assets to ensure uniqueness and verifiability; 5. Improve the transparency and security of supply chain and identity verification; 6. Support DAO governance and realize decentralized decision-making.

The top ten popular digital currency trading platforms in the world include Binance, Ouyi OKX, gate.io, Huobi, KuCoin, Kraken, Bitfinex and Bitstamp. 1. Binance is known for its large trading volume, rich trading pairs, multi-trading mode, high security and user-friendly; 2. Ouyi OKX provides diversified derivatives, localized services, stable technology and Web3 layout; 3. gate.io has the advantages of strict project screening, many trading products, strong compliance, diverse financial products and simple interface; 4. Huobi has mainstream trading products, complete security guarantees, rich activities and localized operations; 5. KuCoin focuses on potential currencies, diversified trading tools, platform currency benefits and multi-language support; 6

Whether an Ethereum perpetual contract is easy to do depends on multiple factors. 1. Its characteristics include no maturity date, capital fee mechanism and high leverage; 2. The advantages are high liquidity, moderate volatility, and support for a variety of strategies; 3. Challenges include high leverage and easy liquidation, capital fee rates affect returns, exchange risks and market manipulation risks; 4. Suitable for short-term traders, arbitragers and hedgeers, not suitable for inexperienced novices or people who cannot withstand high volatility; 5. To improve the success rate, you need to control leverage, set stop loss, pay attention to market sentiment and choose a reliable exchange. Overall, Ethereum perpetual contracts are suitable for experienced traders, but they need to be operated with caution.

The value of stablecoins is usually pegged to the US dollar 1:1, but it will fluctuate slightly due to factors such as market supply and demand, investor confidence and reserve assets. For example, USDT fell to $0.87 in 2018, and USDC fell to around $0.87 in 2023 due to the Silicon Valley banking crisis. The anchoring mechanism of stablecoins mainly includes: 1. fiat currency reserve type (such as USDT, USDC), which relies on the issuer's reserves; 2. cryptocurrency mortgage type (such as DAI), which maintains stability by over-collateralizing other cryptocurrencies; 3. Algorithmic stablecoins (such as UST), which relies on algorithms to adjust supply, but have higher risks. Common trading platforms recommendations include: 1. Binance, providing rich trading products and strong liquidity; 2. OKX,

USDT is not suitable as a traditional value-added asset investment, but can be used as an instrumental asset to participate in financial management. 1. The USDT price is anchored to the US dollar and does not have room for appreciation. It is mainly suitable for trading, payment and risk aversion; 2. Suitable for risk aversion investors, arbitrage traders and investors waiting for entry opportunities; 3. Stable returns can be obtained through DeFi pledge, CeFi currency deposit, liquidity provision, etc.; 4. Be wary of centralized risks, regulatory changes and counterfeit currency risks; 5. In summary, USDT is a good risk aversion and transitional asset. If you pursue stable returns, it should be combined with its use in financial management scenarios, rather than expecting its own appreciation.

USDC is safe. It is jointly issued by Circle and Coinbase. It is regulated by the US FinCEN. Its reserve assets are US dollar cash and US bonds. It is regularly audited independently, with high transparency. 1. USDC has strong compliance and is strictly regulated by the United States; 2. The reserve asset structure is clear, supported by cash and Treasury bonds; 3. The audit frequency is high and transparent; 4. It is widely accepted by institutions in many countries and is suitable for scenarios such as DeFi and compliant payments. In comparison, USDT is issued by Tether, with an offshore registration location, insufficient early disclosure, and reserves with low liquidity assets such as commercial paper. Although the circulation volume is large, the regulatory recognition is slightly low, and it is suitable for users who pay attention to liquidity. Both have their own advantages, and the choice should be determined based on the purpose and preferences of use.

Is DAI suitable for long-term holding? The answer depends on individual needs and risk preferences. 1. DAI is a decentralized stablecoin, generated by excessive collateral for crypto assets, suitable for users who pursue censorship resistance and transparency; 2. Its stability is slightly inferior to USDC, and may experience slight deansal due to collateral fluctuations; 3. Applicable to lending, pledge and governance scenarios in the DeFi ecosystem; 4. Pay attention to the upgrade and governance risks of MakerDAO system. If you pursue high stability and compliance guarantees, it is recommended to choose USDC; if you attach importance to the concept of decentralization and actively participate in DeFi applications, DAI has long-term value. The combination of the two can also improve the security and flexibility of asset allocation.

The ways to obtain USDT include: 1. Purchase through centralized exchanges such as Binance, OKX, etc., which is convenient to operate and supports multiple payment methods; 2. OTC modules are included in the platform for over-the-counter transactions, suitable for large-scale and privacy-conscious users; 3. Use stablecoin exchange platforms or wallets (such as TokenPocket) and decentralized exchanges (such as Uniswap) to achieve cross-chain or cross-currency exchanges; 4. Participate in exchange activities or task platforms to obtain airdrop rewards; 5. Obtain USDT incentives through mining, content creation, community interaction, etc.; 6. Collect USDT directly from other people's wallets, and pay attention to chain type matching to avoid asset loss.