Ever see a sudden massive spike across multiple stocks in the same sector?

Business to business management solution firms like Workday, Adobe, Salesforce, Progress Software, etc all just had a massive spike of anywhere from 10-25% in lockstep all at exactly 2:45 pm.

Is this a glitch in reporting? A massive basket order from a financial institution or a rebalancing of a sector based ETF? Is it a mistake?

Has anyone seen this before and what would be the explanation?