If the acquirer attempts to acquire a startup (regardless of investor) for anti trust reasons, or there are anti trust concerns, the M&A activity is disallowed by regulators. A recent example is Figma and Adobe.
https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...
Seems vague. What is an anti trust reason? Figma and Adobe id a great example. Both are doing very poorly.