IEX vs. SIP Market Data
IEX is a single exchange feed; SIP data consolidates eligible U.S. exchange reports through the consolidated tapes.
Read the draftReal-Time Market Data
Why Can Different Trading Platforms Show Different Prices?
Two screens may be showing different feeds, price fields, timestamps, or trading sessions. First identify what each number measures; only then decide whether either display is wrong.
Draft updated · owner review pending
Compare the same field
A broker's last trade can differ from another screen's bid, ask, midpoint, or previous close. Even two last trades can differ when one feed covers only IEX and the other uses consolidated SIP reporting.
Check time and conditions
Quotes and trades update at different moments. Data can be delayed by entitlement, network, or client refresh. Providers may also apply trade-condition rules when forming bars; Alpaca documents that a minute bar and a daily bar can be affected differently by certain conditions.
A practical checklist
Record the symbol, date, exact event time and time zone, session, feed, field, and chart interval on both platforms. If the mismatch remains after matching these, use the support form without sending API keys or passwords.
Sources and further reading
- Alpaca Market Data FAQFeed coverage, entitlements, and recent historical data
- Alpaca Latest QuotesBid and ask quote fields and feed selection