A major announcement can move stock prices, change market expectations, and trigger trading activity across multiple venues.
But these reactions don't always tell the same story.
That's what makes historical market analysis interesting.
- A stock price shows how shares traded.
- A prediction market reveals how expectations about a specific outcome changed.
- SEC filings help establish what a company has formally disclosed.
When you combine these datasets, you can investigate questions that would be difficult to answer from a stock chart alone.
We've recently introduced Market Replay Labs on the CoinAPI website, bringing together historical data from CoinAPI and FinFeedAPI to examine real events across multiple financial markets.
For FinFeedAPI, it's an opportunity to demonstrate how stock market history, prediction market activity, and SEC filings can work together to provide a more complete picture of an event.
Three Datasets, Three Different Perspectives
Let's take a company announcement.
Historical stock data can show how the market reacted when trading opened, how prices developed throughout the session, and whether the initial movement lasted.
Prediction markets can offer another perspective. Instead of trading the company's shares, participants trade contracts tied to specific outcomes, such as whether a product will launch before a deadline.
SEC filings add important context. They help researchers distinguish formal corporate disclosures from announcements, presentations, and public statements.
None of these datasets replaces the others.
Their value increases when they're analyzed together.
Researchers can compare the timing of market reactions, identify differences between share prices and event probabilities, examine trading activity, and test how various markets respond to the same information.
Episode : Tesla Roadster and Two Very Different Market Reactions
While traditional stock markets were closed, tokenized Tesla climbed to nearly $383.
At the same time, Polymarket's contract for delivery by the end of 2027 dropped from 34.5¢ to 8¢ as production plans shifted toward 2028.
When US trading resumed, the overnight rally faded. Meanwhile, SEC filings showed no Roadster-related 8-K disclosure during the examined period.
One event, different market reactions.
By combining stock history, prediction markets, and SEC data, researchers can see not only how prices moved, but how expectations changed and what information was available.
What Can Researchers Learn From This Approach?
The Tesla example illustrates several opportunities for financial research.
- Compare expectations with market prices. A company can generate enthusiasm among investors while participants in prediction markets become less confident about a particular milestone. Understanding that difference can provide useful context for event-driven analysis.
- Study reactions across trading sessions. Announcements don't always happen during regular market hours. Combining stock history with other continuously trading markets makes it possible to examine what happened before the next cash session.
- Measure the timing of information. Historical trades, timestamps, and market activity can help researchers investigate when a specific piece of information was reflected in prices or probabilities.
- Add corporate disclosures to the analysis. SEC filings provide a separate source of evidence, helping distinguish regulatory disclosures from other public announcements.
- Build more informed backtesting and AI workflows. Multiple historical datasets allow developers to examine relationships between market movements, changing expectations, and documented events rather than relying on price data alone.
These insights aren't limited to product launches. The same approach can be applied to earnings announcements, regulatory decisions, mergers, and other events where market expectations and asset prices may respond differently.
Explore Market Replay Labs
Market Replay Labs is a new research section on the CoinAPI website, powered by data from CoinAPI and FinFeedAPI.
Each episode brings different markets onto a shared historical timeline, allowing readers to examine actual trading activity, compare market reactions, and explore the API requests behind the analysis.
FinFeedAPI provides the historical stock data, prediction market data, and SEC filings that help connect price movements with expectations and corporate information. CoinAPI adds cryptocurrency and tokenized asset market data.
Together, they make it possible to investigate historical events from several perspectives, with the underlying observations traceable to their sources.
Our first episode, covering the Tesla Roadster unveiling, is now available on CoinAPI.
Explore the replay and see what different financial datasets can reveal when analyzed together.
