What is a live price feed?

Each update in a feed is called a tick. A tick carries the instrument, a bid price (what you can sell at), an ask price (what you can buy at) and a time. In busy markets an instrument can tick many times a second; in quiet hours it may not tick for a while.

What the feed drives in a prop firm

• The terminal: the prices on the watchlist and the moving chart.
• Fills: market orders execute at the current bid or ask.
• Pending orders and stops: they trigger when the price crosses their level.
• Equity: floating profit and loss is recalculated as prices change.
• Rules: loss limits are judged against equity at each new price.

Why tick-level handling matters

If a platform samples prices every few seconds instead of using every tick, a short spike can cross a loss limit and recover between samples. The account should have breached, but the system never saw it. The reverse also happens: a sample taken during a brief spike can breach an account that the market only touched for an instant on a wide spread.

What to ask a provider

• Is the rule engine fed by every tick, or by periodic snapshots?
• Are ticks processed in the order they arrive?
• What happens if the feed pauses?

PropExecutor's rule engine judges every account on each price tick, in the order the ticks arrive, using a queue that never drops a tick, so a fast move cannot slip past a limit unseen.