Polling checks for signals on a schedule. Webhooks deliver them the instant they fire. For automated trading, the difference isn't academic, it's slippage.
Automate your trading strategy
Start Free TrialWhen you automate a trading strategy, something has to detect when a signal fires and then act on it. How that detection happens determines how fast your bot responds to the market.
Two fundamentally different approaches exist: polling and webhooks. Most traders use whichever their platform defaults to without knowing there's a choice, or what that choice costs them.
What polling is
Polling means your system checks a data source on a fixed schedule. Every N seconds, it asks: "Has anything changed?" If yes, it acts. If no, it waits and asks again.
Think of it like checking your email by refreshing your inbox every 30 seconds. You'll eventually see new messages, but you always see them a little late, and the delay depends entirely on when in the cycle the message arrived.
In trading automation, a polling-based system might check your signal source every 5 seconds. If a signal fires 1 second after a check, your bot won't see it for another 4 seconds. That 4-second gap is latency you pay on every signal: invisible in backtests, real in live fills.
What webhooks are
Webhooks flip the model. Instead of your system asking "has anything changed?", the signal source pushes a notification the instant something happens.
Your system isn't checking. It's listening. When the event fires, the webhook payload arrives within milliseconds.
For trading: when your TradingView alert fires, a webhook immediately sends the payload to RelayDesk. There's no polling interval to wait through. The full round trip, from your alert firing on TradingView to your order reaching your broker, typically runs under 500ms end to end. RelayDesk's own processing, from the moment a webhook lands to the moment an order is sent to your broker, adds under 50ms of that total.
Why this matters for your fills
Consider a momentum strategy on a 1-minute chart. The signal fires at 10:32:07.
Your target entry is near the candle's open at 10:32:00. A 5-second polling system catches the signal at 10:32:11.
The market has moved. You're filling at a worse price than your backtest assumed.
On a slow-moving position trade in a large-cap stock, 4 seconds of latency is irrelevant. On a fast-moving small-cap with a tight entry window, it can mean the difference between a valid fill and chasing the move.
Strategy type vs. execution architecture
Position trades and swing trades held for hours or days can absorb polling latency without meaningful impact. A few seconds won't move your fill price enough to matter.
Daily setups and intraday momentum plays benefit measurably from webhook delivery. Polling on a 5-second interval means you're always working with slightly stale data. Your fills are consistently behind the signal.
Scalping and high-frequency strategies, where entries must be precise, are nearly impossible to run reliably through polling. The latency kills the edge.
The hidden cost: compounding latency
Polling latency doesn't just affect one trade. It compounds across your entire track record.
If your polling system adds an average of 2.5 seconds of delay to every entry and you take 100 trades per month, that's 100 fills that were systematically worse than your strategy assumed. The gap between your backtest and live performance widens in ways that are hard to attribute because the latency is consistent and invisible.
Webhook-native execution eliminates that systematic bias. Your fills happen as close to signal time as network latency allows. No polling interval compounds on top of that.
Choosing your stack
When evaluating automation platforms, ask one question: does signal detection happen on an interval, or the moment the signal fires? Polling-based systems are simpler to build but introduce structural lag.
Webhook-native systems require a receiving endpoint and real-time processing infrastructure. The tradeoff is reliability and execution speed.
RelayDesk is webhook-native. Every alert from TradingView is received and processed the moment it fires. There's no interval to wait through and no missed window because a check ran a second too early. For strategies where execution timing matters, that architecture is the foundation your edge depends on.
RelayDesk is a trading automation platform. We are not a broker-dealer or investment advisor and do not provide investment advice. Trading involves substantial risk of loss. Past performance is not indicative of future results. View full disclaimer