What is a broker requote and why does it happen?

Market execution vs instant execution — what is the difference?

Instant execution fills at the quoted price or rejects with a requote. Market execution fills at the best available price — no requote, but possible slippage. ECN/STP brokers use market execution because the order is routed to liquidity providers; market-makers offer instant execution because they're the counterparty. Market execution is faster and more transparent.

What is an ECN forex broker?

An ECN (Electronic Communication Network) forex broker routes client orders directly to a pool of liquidity providers without running a dealing desk. ECN brokers charge a commission per lot instead of marking up spreads, resulting in lower all-in costs and no conflict of interest with clients.

STP vs ECN broker — what is the difference?

STP (Straight-Through Processing) routes orders directly to liquidity providers without dealing desk intervention. ECN (Electronic Communication Network) connects multiple liquidity providers and traders, with prices set by the order book. ECN brokers typically charge commission with raw spreads; STP brokers often work commission-free with wider spreads. For active traders, ECN usually beats STP on total cost.

Article: Slippage at News Events — A Broker-by-Broker Comparison Methodology

Slippage at high-volatility news releases is the single most important execution-quality differentiator across retail forex brokers. A repeatable methodology for measuring it produces materially different rankings than headline-spread comparison.