What is the central principle of algorithmic trading?

• A. If this happens, do this.
• B. Always buy and hold.
• C. Trade randomly.
• D. Ignore market data.

Answer: (A)

Rule-based automation lies at the heart of algorithmic trading: you specify precise market conditions and the corresponding action, and a computer executes the trade when those conditions are met. This approach hinges on objective triggers and predetermined responses, making decisions fast, repeatable, and easy to test against historical data. The idea captured here is a clear condition-and-action structure, which is exactly how automated trading rules are encoded and executed based on market data. The other options don’t fit because they either rely on a passive stance, lack any defined triggers, or ignore data, which defeats the purpose of a data-driven, automated strategy.