Each option resolves YES if Manifold starts paying interest within 2% of the US treasury rate.

Motivation: Interest payments would make it substantially more attractive to bet on long-term markets, and would set Manifold apart from other real-money prediction markets. Interest could be paid if Manifold invests its cash assets in treasuries.

Paying interest may present significant legal challenges to Manifold as a business, however I wonder if the Sweepstakes model might make this possible, presenting a significant competitive advantage. (Perhaps this works if the payments are called 'rewards' rather than 'interest'.)

Resolution details:
E.g., if I hold 100,000 YES shares in the market Will Eliezer Yudkowsky win his $150,000 - $1,000 bet about UFOs not having a worldview-shattering origin? now, and in 6 months I would automatically own 102,000 YES shares despite not buying any new ones, the option "On Shares in a market" will resolve YES.
It doesn't matter whether it's called 'interest' or 'rewards' or some other term (e.g. chosen for legal reasons), as long as it has a roughly similar effect.
For an option to resolve YES, interest can be paid in any currency (Shares, Mana, Prize Points, USD, or any currency of similar value).

It resolves YES if interest paid corresponds to any of the short- or long-term interest rates listed here ±2%, though the interest rate needs to be positive (above zero).