The contrarian bet is fun but I wonder how it actually holds up. Prediction markets do tend to overprice dramatic outcomes, so "always bet no" isn't as dumb as it sounds. Would love to see real P&L over a few months, not just the thesis.
I'm pretty into prediction markets and have some strategies that make me small, but consistent returns.
I think timing is the missing piece of this. Just randomly betting no on everything likely isn't going to give good results, but if you tied in a news API and just bet no on anything related to a major story right after the news starts picking it up, I would expect you could make a solid return.
I've backtested this kind of strategy, and it had a good return (like 100% APR), but then I realized it was cheating by knowing when things are going to resolve. Often times it's not clear. Your return depends a lot on how quickly you can get your money out. I never got around to trying a strat that doesn't know the resolution time, which actually has to be manual cause it takes some judgement to pick things that you expect to resolve soon.
Also requires a lot of volume to be "predictable" obviously, since 1 loss sets you back 10-20 wins. It's surprisingly hard to find reasonable-liquidity markets after all your filtering. Many have huge spreads or thin books. Scare quotes around "predictable" because you never know if others will use this strat or a lot of unlikely events will happen due to insiders.
Another thing, just like the author, I was excluding sports in all the above. Yes Polymarket is famous for letting people bet on world events etc, but turns out it's still more about sports. Betting on the overdog in sports markets seems more appealing because there are plenty of those events with large volume, they're kinda homogenous, you know exactly when they resolve, and they're harder to rig. I simply never got around to putting real time or money into the overdog strat.