What was your best passive income in 2021?

I let a realtor put up a billboard sign on my property next to the highway for $500 a year. It covers my layer hen feed costs and if they decide they dont want it, or go out of buisness, I get to keep the sign which I can paint into an "Eggs 4 Sale" sign.

Other than that, I made a few bucks mining crypto but nothing spectacular.

Passive: Stonks, RE, ponzi coins going up in value

Hustle: Selling Trezor Ones on eBay in Australia. They were hot cakes a few months ago but it’s slowed down now so stopped it.

I have two main passive incomes:

Cardano Staking - My holdings have grown 3x this year. (~$2300/month)

Industrial Real Estate - Holdings have remained stable mostly, with a few upsets. Have super stable tenants in industrial spaces that they have little incentive to leave. This is with an investment group, so I'm only own 5-10% of the building through LLCs. (~$2700/month)

I keep toying with a few SaaS ideas in the logistics space, but haven't earnestly launched anything. This is a library I'm working on slowly, and I think it has legs to have a commercial offering. I know it won't be passive, but one can dream :D

https://github.com/dhruvkar/tracktrace

Farming chia crypto - got in on day one, was still behind compared to people in beta. I also started selling niche mushroom cultivation tools, in part because growing gourmet mushrooms was a hobby I picked up during quarantine.

Selling NFTs. Primary sales aren't passive, it's a second full time job making them, but royalties of secondary sales are passive.

Selling options.

Lumber

RE.