Examples of spillover effects that occurred fairly recently include an earnings announcement from Illumina on Feb. 11—it disappointed the markets and its stock price went down immediately 5.5%. Over the ensuing week, Agilent Technologies, another biotech and scientific research company, also saw their stock price decline by 11.80%.

How firms use powerful computer programs to trade much faster than a human can

In addition, the researchers found that when companies as ubiquitous as Apple announce higher-than-expected earnings, they could lift the whole market up because it would be a sign of consumers having more discretionary spending. The inverse effect would occur if Apple’s earnings disappoint. Earnings announcements…