Inspired by this tweet.
"Universal basic income" is any amount of money or other items of value given to at least 90% of residents/citizens of any large jurisdiction, where the amount is sufficient for them to have a reasonable living on that income alone.
"Large jurisdiction" means any state, country, or other defined geographically-contained entity containing at least 1 million people.
"Mass suicide" means that the average suicide rate over the next 5 years must be at least twice the suicide rate in the 5 year period prior to UBI being implimented.
If the UBI is ended before 5 years have elapsed (temporary inturruptions notwithstanding), that doesn't count for this market, unless a primary reason for ending it was due to increased suicide rates.
This market remains open until the first qualifying instance of UBI, and then resoves to the result.