Will-it-happen versus who-the-crowd-backs
Prediction markets are built around events with a real-world answer. Will a candidate win the election? Will a team make the playoffs? Each one is settled by what actually happens — an official result everyone can check.
Opinion markets are built around debates. Who is the GOAT? Best album of the decade? Best city to live in? None of these have a real-world result to wait on. They are arguments, and the winner is whichever side the crowd ends up backing the most.
Why an outside result cannot settle a debate
A prediction market needs a referee — a scoreboard, an official source, a final number. That works beautifully when the question has one correct answer. It falls apart for "greatest rapper alive", because there is nothing to look up and no body that can declare a winner.
An opinion market removes the referee entirely. The market decides its own winner: when one side holds the lead long enough, the crowd has spoken and the market agrees.
Why the crowd is the right judge for opinions
For a subjective debate, the question is about collective judgment in the first place. And the most honest signal of collective judgment is what people will back with money. Anyone can post a take; far fewer will put real conviction behind it.
That is what makes a market a better read than a poll, a vote, or a like count. The price reflects real positions from real people — a much higher bar than a comment.
Same topic, two different questions
Most subjects can be framed either way, and the framing decides which kind of market can host it. Politics: "will candidate X win?" versus "should candidate X win?". Sports: "will Team A beat Team B?" versus "who is the GOAT?". Music: "will this album go #1?" versus "best album of the decade?".
The first column needs a real-world result. The second needs the crowd. Morfi is built for the second.