What determines when a Polymarket market is listed and open for trading?

Is Polymarket better than using polls or betting sites for predictions?

What’s the best time to enter or exit a Polymarket position?

How is the last traded price determined if the spread is wide on Polymarket?

What is the difference between a market proposal being accepted vs rejected on Polymarket?

How does Polymarket maintain that no “house” is the counterparty for its users?

How frequently are new markets added to Polymarket?

What’s the best way to find good markets to trade on Polymarket?