Wow! I heard that prediction markets are really popular lately! I just saw that Kalshi and Polymarket's trading volume in November nearly reached 10 billion dollars. That's incredible! As a newbie just entering the space, I don't really understand how this works. Can any experts explain what prediction markets are for? Why is there such a huge trading volume? I feel like I've discovered a new world and really want to learn more! But seeing such large numbers also makes me a bit worried—could this be a bubble? I hope to find reliable introductory materials and learn gradually.