Advantest is a larger part of an ATE duopoly with Teradyne.

Source: https://seekingalpha.com/article/4621559-advantest-tough-quarter-but-expect-strong-recovery?source=feed_all_articles

Mr Fisher says he is standing for Cootamundra to help "break the Labor LNP duopoly".

Source: https://www.boorowanewsonline.com.au/story/8105783/cowra-based-independent-to-stand-for-cootamundra/?src=rss

Since any major overhaul of the voting system requires both parties to sign on, that is extremely unlikely to happen since it will undermine the duopoly they currently reap the benefits on.

Source: https://news.slashdot.org/story/23/07/10/2323208/majority-of-americans-say-tiktok-is-a-threat-to-us-national-security?utm_source=rss1.0mainlinkanon&utm_medium=feed

Speaking at the Express Adda on Saturday, he allayed concerns of a duopoly emerging in the market with weakening financials and dropping market share of Vodafone Idea Ltd. “No, we are not heading towards a monopoly.

Source: https://www.financialexpress.com/industry/india-will-not-have-a-monopoly-or-duopoly-in-telecom-sector-ashwini-vaishnaw/3099178/

The candidate of the incumbent APC may have won, but the era of the APC-PDP duopoly, in place since the return to civil rule in 1999, seems over.

Source: https://allafrica.com/stories/202303020001.html

While any company has the ability to compete with Apple and Google under the DMA, Meta is one of the few companies that has the scale, reach, and brand to be able to make a dent in the app store duopoly.

Source: https://www.webpronews.com/meta-is-preparing-to-compete-with-apple-and-googles-app-stores/