15 October 2026 · 3 min read

Where exchange price data comes from, and what it costs

Nearly three in ten exchange briefs ask for a live price feed. Here is where the numbers come from, which ones are free, and why your own book should not quote your own chart.

"Live price feed" appears in around three out of ten real exchange briefs, usually written as one line next to the chart. It is rarely one line of work, and the choice behind it affects what your venue costs to run every month.

Three different numbers people call "the price"

They get confused constantly, and they are not interchangeable.

• Your own last traded price. What your matching engine filled at. True for your venue, and meaningless when your book is thin.
• A reference price. What the asset trades at on large venues, used for display, risk checks and valuations.
• A quote. What you are willing to buy or sell at right now, which is a reference price plus your spread and your inventory position.

A new venue that shows its own last traded price as the headline number will show something embarrassing the first time one trade moves it twenty percent.

Where the data comes from

Public exchange APIs. Free, rate limited, and geo blocked in places. Perfect for a marketing ticker, acceptable for a reference price if you handle failure, and risky as the only source for anything financial.

Aggregators. Paid tiers with an SLA, wider coverage and historical data. This is what you move to when the number starts mattering.

Your own book. Free and only meaningful once you have real volume.

Charts. A charting library is not a data source. TradingView's widget is free and carries their data and branding; their charting library plugs into your feed, which means you need the feed first.

If a wrong price costs you money rather than embarrassment, you need a paid feed with a contract behind it. If it only costs you embarrassment, free sources with a fallback are fine.

The engineering that is not in the line item

• Failure behaviour. When the source is down, does the chart go blank, freeze on the last number, or hide itself? Never show a stale number as live.
• Rate limits. One request per coin per second across eight coins is eight times more traffic than you need. Batch, cache, and poll slowly.
• Normalisation. Different venues, different symbol names, different decimal conventions.
• Decimals. Prices are not floats. Rounding errors in financial code are not cosmetic.

The live ticker on this site is the cheap version of exactly this: one batched request, polled every thirty seconds, Binance first, a second source as fallback, and the bar removes itself rather than showing a stale number as live.

What it costs

• Marketing ticker or simple reference price: free, with care.
• Risk checks, valuations or anything a user can trade against: a paid tier, usually tens to low hundreds of dollars a month depending on coverage and update rate.
• Historical data for charts going back years: priced separately, and the line most people forget.

Those bills go from the provider directly to you, in your name, like hosting and KYC. The full cost breakdown puts them in context.

Questions

Is there a free crypto price API

Yes, several public exchange APIs are free and rate limited, and aggregators have free tiers. They are fine for display, and inadequate as the only source behind anything financial, because you have no guarantee and no recourse when they fail.

Can I use TradingView charts on my exchange

Yes. The free widget carries their data and branding. Their charting library renders your own data, which means you need a feed of your own first. The two often get confused when a brief says "TradingView charts".

What price should my exchange display

A reference price from outside while your own book is thin, clearly labelled, with your own last traded price shown where it belongs. A thin book quoting itself produces numbers that scare users away.

How much does market data cost for an exchange

Free for display with care. Tens to low hundreds of dollars a month once the number has to be reliable, and historical data for charts is usually priced separately.

What happens when the price feed goes down

It should fail visibly and honestly: hide the number or mark it stale, never keep showing an old price as if it were live. That rule matters more than which provider you choose.

Do I need a price feed for a swap platform

Yes, and it is the core of it. A swap quotes from a reference price plus your spread, so the feed is not decoration there, it is the pricing engine.