Two browser tabs open to the same ticker can show two different prices. Sometimes they're a few cents apart; sometimes they're more. The reason is almost never an error — it's that "the price of a stock" is a less precise idea than it looks. This page explains where market data comes from, what "real-time" actually means in practice, and when the difference between real-time and a 15-minute delay matters versus when it doesn't.
Where prices come from
A stock's "price" is whatever the most recent trade printed at — and trades happen on exchanges. Major US equities trade across many venues simultaneously: NYSE, Nasdaq, BATS/Cboe, IEX, and others. The Securities Information Processor (SIP) consolidates quotes and trades from these venues into a single feed. Vendors then take SIP data (or direct feeds from individual exchanges) and redistribute it.
Crucially, exchanges charge for distributing real-time data, especially to non-professional users. Free tiers of most data products show delayed data — typically by 15 minutes for US equities, sometimes more for international markets — because that delay puts the data outside the exchanges' real-time licensing tier.
What "real-time" actually means
"Real-time" is not literally instantaneous. There is always some latency between a trade printing on an exchange and a quote appearing in your browser, made up of:
- The exchange-to-vendor hop (typically milliseconds for direct feeds, slower for SIP-derived data).
- The vendor's internal processing and distribution.
- The network hop from the vendor to your browser.
- Throttling. Free or low-tier feeds may publish updates only every few seconds even when the underlying market ticks much faster.
For a retail reader looking at a chart, "real-time" usually means a quote within a second or two of the SIP. That is plenty for most purposes; it is also not the same thing as the millisecond-resolution feed a market-maker uses.
Why two sources can disagree
Even between two real-time sources, identical prices at the same instant are rare. Common reasons:
- Different feed. One source may be using SIP, another a direct exchange feed; they don't update in lockstep.
- Different field. "Last price" (last trade), "mid" (between bid and ask), and "bid" or "ask" are not the same number. Quote pages don't always make clear which they're showing.
- Different exchange. A stock dual-listed in New York and Toronto can have moment-by-moment differences as each market reacts independently.
- Throttling. One vendor publishes every 1 second, another every 5. Within that window the displayed values diverge.
- After-hours and pre-market. Outside regular hours, fewer trades happen and "the price" depends heavily on which venue's last trade you're seeing.
When the delay matters and when it doesn't
It usually doesn't matter for:
- Long-term research. If you're sizing up a buy-and-hold position over months, a 15-minute delay on a daily chart is invisible.
- Reading fundamentals. P/E, market cap, dividend yield — these update on quarterly cadences. See key financial ratios at a glance.
- Educational chart-reading. The shape of yesterday's chart is the shape of yesterday's chart.
It can matter for:
- Active trading. Anyone placing market orders during the session needs current bid/ask, not delayed last-trade. Use the live quote in your broker, never a third-party page.
- Earnings and other catalysts. A delayed quote during the first 15 minutes after an earnings release can be wildly different from the live print.
- Thin tickers. Low-volume names can move a few percent between trades. Even small delays accumulate uncertainty.
- Crypto. Crypto markets trade 24/7 across many exchanges, each with its own price. There is no single "real-time" — there is a price on each venue, and they're typically a few basis points apart.
Comparing data sources
If you ever need to verify a number, three things are worth checking:
- Which feed? Direct exchange, SIP, or aggregated. Most consumer pages don't say.
- Which field? Last trade, mid quote, official close, adjusted close (for splits and dividends). These can differ by several percent on the same day.
- What timestamp? A current-looking number with a timestamp 18 minutes old is delayed data, regardless of what the page calls it.
A short worked example
You see a ticker quoted at $50.12 on one site and $50.08 on another, with a 4-cent spread between bid and ask. Both numbers can be correct simultaneously — one is showing the last printed trade, the other is showing the mid of the current quote, and the trade printed against the bid. You'd see a third number if you opened your broker, because the broker is showing the live ask you can actually buy at right now. None of the three is wrong; they're answers to slightly different questions.
What this site shows
StockTicker.net embeds market-data widgets from TradingView. The price you see depends on TradingView's licensing and your visitor profile — for many US tickers it is real-time, for some international or thinly traded ones it is delayed by exchange policy. TradingView marks delayed symbols in its own interface (for example with a delay notice next to the exchange name in the full chart), but the compact widgets do not always make it obvious. If a number is critical, cross-reference it with your broker. See the Disclaimer for the full caveat.
Frequently asked questions about delayed data
Why is free stock market data delayed 15 minutes?
Exchanges own their market data and charge licence fees for real-time distribution, with separate (and usually higher) fees for professional users. Data that is shown at least about 15 minutes after the fact generally falls outside those real-time display fees, so websites and apps that do not pay them show delayed quotes. The 15-minute figure is a licensing convention set by the exchanges, not a technical limit; some venues and international markets use 10, 15 or 20 minutes, and some show end-of-day data only.
What does “NYSE quote data delayed” (or “delayed quote”) mean?
It means the price on screen is the last trade or quote as of roughly 15 minutes ago, not now. The chart and the day's high/low are also lagging by the same amount. The label is a licensing disclosure: the site is not paying for real-time NYSE (or Nasdaq) display rights for your account.
How do some free sites show “real-time” US prices?
Many free platforms show real-time prices from a single venue or a lower-cost exchange product (for example a Cboe or Nasdaq last-sale feed) rather than the full consolidated tape from every exchange. Those prices are genuinely current, but they only reflect trades on the venues included, so they can differ slightly from the consolidated price your broker shows, especially in thin or fast markets.
Why do some international stocks show real time and others don't?
Each exchange sets its own licensing terms. A platform may have a real-time agreement with one exchange but only delayed rights for another, so the same app can show live US prices next to a delayed London, Tokyo or Indian quote. Look for a delay marker or the time stamp beside the price.
Why does TradingView, Yahoo Finance or my broker show a different “real-time” price?
They may use different feeds (single venue vs. consolidated), different fields (last trade vs. bid, ask or mid), and different update throttling. During pre-market and after-hours trading, prices can differ more because fewer trades happen and each venue's last print is different.
Does a 15-minute delay matter for investors?
For long-term research, fundamentals and learning to read charts, rarely. For active trading, around earnings releases, or in thinly traded symbols it can matter a lot. Anyone placing an order should look at the live bid and ask in their brokerage account, not a delayed web quote.
Do stock market simulators use delayed data?
Many do. Free paper-trading and simulator apps commonly fill orders against delayed prices (often 15 to 20 minutes behind), which makes fast strategies look better or worse than they would in reality. Check the simulator's data notes before drawing conclusions.
Common mistakes
- Treating any free quote as real-time. If the source doesn't say so explicitly, assume some delay.
- Comparing intraday quotes from different sources second by second. A small price gap between two free pages is usually a feed difference, not a discrepancy.
- Trading off a website price. Use a broker's live quote, especially for market orders.
- Forgetting that crypto has no SIP. "BTC at $X" is shorthand for "BTC at $X on this exchange right now"; on another exchange it might be a different number.
Extended-hours prices are a common source of confusion — see stock market hours. For the raw trade-by-trade data behind every quote, see tick data explained. For the chart that displays this data, see how to read a stock chart. For an introduction to the indicators on top of it, see common technical indicators explained.
This page is general educational content and not investment advice. See the Disclaimer.