I spent weeks, burned through millions of LLM tokens, tested BTC and ETH binary markets from 5-minute slots all the way to 4-hour windows, deployed bots across multiple VPS instances in Amsterdam, tuned 40+ config parameters, and wrote probably 3000 lines of Python trying to find edge in Polymarket's Up/Down markets.

Here's what I found: there isn't any. Not for me, not for you, probably not for most people reading this.
The math is clean and brutal. When both sides fill, you pocket roughly 7 cents per dollar. That part works. The problem is what happens the other 85% of the time — when only one side fills and you're stuck holding a coin flip.
Except it's not a coin flip. You consistently lose at 30% win rate on those single-sided positions. Random would give you 50%. The market is smarter than your bot. Every order you get filled on the "good" side, there's a professional already on the other side who knows something you don't, or the slot resolves 30 seconds later and you're the last one holding.
A friend told me to drop this months ago. He's been in these markets longer than me. I ignored him because I had Claude, Codex, and a terminal setup that felt like an actual trading desk. "This time the tooling is different." It wasn't.
The irony: the more sophisticated my bot got, the more efficiently it lost. v1 lost $122 in 48 hours. v2 added hedging features and lost the same amount. v3 deployed on faster VPS with more guards and locked $670 in frozen positions because I picked the wrong wallet type. By v4 I had 8 concurrent instances across 4 markets and still couldn't crack a 43% break-even threshold on unhedged fills.
This is Solana trenches logic applied to market making. You log in thinking today's the day you finally beat the house. There are 99 predatory participants for every one legitimate edge in these markets. The moment you click buy — in this case, the moment your order gets filled — someone already knew more than you.
Polymarket's binary markets are genuinely efficient. Not perfectly efficient, but efficient enough that automated market making at retail scale is a grind for maybe $1-2/day with real capital at risk. That's not passive income, that's fee extraction on capital you're slowly burning.
Where I think edge still exists: anything that requires reading fast-moving information — Trump tweets, Elon posts, breaking news that hasn't been priced in yet. The markets that are slow to update. Not the ones with professional quoting bots sitting at the spread 24/7.
If you're thinking about building something similar: test first, talk to people who failed before you, and don't mistake the ability to build it for a reason to build it.
I had the army of terminals. Turns out the horse didn't care.