4. Realtime vs Delayed Data

Charts can update live as new bars arrive. How fresh those updates are depends on your provider and plan.

Streaming updates

When a stream is available, the latest bar updates in place as trades come in, and a new bar is appended when the interval rolls over. The candle info line and any indicators recompute against the forming bar.

Live price level

When a provider exposes a raw trade (tick) feed, the chart also draws a live price line that moves with each individual trade, independent of the bar series. It rides the same streaming connection as the bars — no extra connection is opened — and replaces the built-in last-value line so the chart shows a single, consistent price line styled to match your symbol price-line settings.

Trades only move this price level; they are never aggregated into bars (the bar series keeps updating from the provider's bar stream). The live line is best-effort and falls back to the normal bar-driven price line whenever it can't be shown — the provider has no trade feed, your plan isn't entitled to one, the channel errors, or no trade has arrived for about 30 seconds (for example, when the market is closed). It is not shown during bar replay.

Live prices are available for Massive and Alpaca (US equities) and Binance (spot and futures), subject to the same feed/entitlement rules as the bar stream below.

Massive: realtime or delayed

For Massive (equities), the websocket feed can be realtime or delayed:

• Realtime — live updates, for realtime data plans.
• Delayed — delayed updates, for delayed plans.

Set the default feed with the MASSIVE_STOCKS_WS_FEED / NEXT_PUBLIC_MASSIVE_STOCKS_WS_FEED environment variables, and override it per browser under Settings → Data provider → Massive → Streaming. Choose delayed if your Massive plan is delayed; use realtime (or omit it) for realtime plans. See Configuring Providers & API Keys.

Alpaca: IEX or SIP

For Alpaca (US equities), the equity data feed can be IEX or SIP:

• IEX — the free-tier feed (default). It only reflects trades on the IEX exchange, so bars stream during market hours but are sparse for less-active symbols.
• SIP — the full consolidated feed; requires an Alpaca subscription that includes SIP.

Set it via ALPACA_DATA_FEED / NEXT_PUBLIC_ALPACA_DATA_FEED or under Settings → Data provider → Alpaca → Data feed. Realtime stock bars only flow during US market/extended hours.

Alpaca permits a single concurrent data-stream connection per account, so the app opens one websocket and multiplexes every open Alpaca ticker over it (subscriptions are reference-counted and reused across panes). Alpaca streaming here covers US stocks only — there is no Alpaca crypto in this app.

Binance: public realtime

Binance crypto data streams from public Spot websocket endpoints in realtime, with no key or plan selection required. Perpetual futures stream from Binance's public USDⓈ-M futures websocket (fstream.binance.com) in the same way.

OKX: public realtime

OKX crypto data streams from the public OKX v5 business websocket (ws.okx.com) in realtime, with no key or plan selection required. Spot pairs and linear perpetual swaps both stream from the same endpoint using the candle* channel. The connection sends a periodic ping to keep the socket alive, which OKX requires roughly every 30 seconds.

Forming vs. confirmed bars

The most recent bar is forming until its interval closes, after which it is confirmed. Studies and strategies distinguish the two so a signal on the live bar is understood as provisional until the bar closes — relevant when authoring indicators and strategies.

Next steps

You have covered data and symbols. Next, organize symbols with watchlists.

Next: Watchlists Overview