How to Trade News on Prediction Markets

News can change what an event contract is worth to a participant. That does not mean a headline provides an executable advantage. Other participants may already know it, the quote may have moved, and the story may concern a different outcome from the contract's actual settlement rule. Research the response before treating speed as a strategy.

Start with the contract and the information

Read the exact outcome, deadline, settlement source and exceptional rules. A reported result, a certified result and a particular statistic can describe different contracts. Even apparently similar sports or political markets may use different definitions. Ordinary binary contracts are common; do not assume every product has only a zero-or-one payout.

Write down the hypothesis before examining later prices. Specify which information qualifies, how it maps to a market and what observable response would contradict the hypothesis. A manually labeled announcement study can be useful without claiming to estimate a true probability or placing any orders.

Keep three times separate

An article's publication timestamp is different from when your process received it and when your process observed a quote. Sources may revise timestamps or content. Clocks may disagree. Store the raw source identifier, available source time, local receipt time, content version and quote provenance. Do not substitute a later corrected headline for the text available at the decision time.

This standalone research helper measures only an observed local interval. Its inputs must be timezone-aware datetimes from a comparable clock. It rejects negative intervals rather than quietly calling them fast reactions. It neither estimates exchange latency nor supplies a signal to Banger.

from datetime import datetime, timezone

def observed_delay_seconds(news_received, quote_received):
    for value in (news_received, quote_received):
        if not isinstance(value, datetime) or value.utcoffset() is None:
            raise ValueError("timezone-aware datetimes required")
    delay = (quote_received.astimezone(timezone.utc)
             - news_received.astimezone(timezone.utc)).total_seconds()
    if delay < 0:
        raise ValueError("quote precedes the recorded news receipt")
    return delay

# Hypothetical observations, not a venue measurement.
news = datetime(2026, 10, 1, 12, 0, 0, tzinfo=timezone.utc)
quote = datetime(2026, 10, 1, 12, 0, 2, tzinfo=timezone.utc)
assert observed_delay_seconds(news, quote) == 2

An earlier quote may also be useful as the pre-announcement comparison. Keep it separately; it is not a post-receipt reaction. If the feed has gaps, your first observed change may be later than the actual change. A missing measurement belongs in the results rather than disappearing from the sample.

Evaluate available prices and costs

Use the appropriate bid or ask for the intended side, available size and timestamp. A displayed midpoint or last trade is not a promise of a fill. Historical price points alone cannot reconstruct the order queue, all depth or what competing orders would have done during the announcement.

Account for fees, spreads, partial execution and the possibility that only one action succeeds. Different receipt-to-decision delays can be useful hypothetical stress scenarios, but they do not turn a coarse historical series into a measured execution replay. Include unchanged prices, ambiguous announcements and unsuccessful observations, not just striking examples.

Integrate cautiously with paper research

Banger's public product is for paper research. The public SDK callback is on_market_tick(market, tick, ctx). An on_event(event, ctx) hook also exists, but its presence does not mean the platform automatically collects external news or delivers a news-specific schema. A separate connector and mapping would need their own validation.

The packaged Kalshi adapter can fall back to public REST polling when WebSocket credentials are absent. The Polymarket adapter has a market-stream path. Neither statement proves complete news timing, lossless delivery or a profitable response. Log bounded observations and inspect the actual feed path before comparing latency.

Define a limited conclusion

A study can support a description of observed quote changes under its data and timing assumptions. It cannot establish legal permission, guaranteed profit, correct settlement or a production trading system. Public accessibility also does not settle every permitted-use question. Preserve the raw evidence and report what the study could not observe alongside what it found.