A guide to global trading that satisfies different circles! This article deeply dissects the practical applications of Contracts for Difference (CFD) products in three core scenarios: analyzing how office workers use the T+0 mechanism and mobile terminals for fragmented wealth management; exploring how small-capital entrepreneurs use micro contracts, margin systems, and position calculators to achieve refined risk control; and revealing how professional traders use open API interfaces to seamlessly integrate algorithmic models and quickly match quantitative strategies.