Resolution will be based on Nintendo Investor Relations data.
https://www.nintendo.co.jp/ir/en/finance/hard_soft/index.html
As of the March 31st, 2023 update to their numbers, the Switch has sold 125.62 million units so far.
The current best-selling videogame console of all time at the time of market creation is the Playstation 2. The last official sales number from Sony with regards to the Platstation 2 is 155 million units, so this will be the number to beat, unless Sony updates this to a higher number at some point. (https://sonyinteractive.com/en/our-company/business-data-sales/)
Update: the new number to beat is 160 million units following an update from Sony
If Nintendo report that the Switch has sold more than the PS2 at any point before 2026, this market will resolve YES. If they don't, NO.
1,000
3.00
A Switch 2 is heavily rumoured for 2024. Not sure the current switch will sell 30m in the next two years if a successor is already on the market. For comparison PS4 sales have decreased massively since the release of the PS5 in 2020: https://sonyinteractive.com/en/our-company/business-data-sales/