The New Gambling Epidemic: Sports Betting, Kalshi, Day Trading, and Halacha

Gambling has moved from casinos to our phones.
FanDuel, DraftKings, BetMGM, ESPN Bet, Kalshi, and day-trading platforms have made “action” available every minute of the day.
When is risk-taking legitimate, and when does it become gambling?
Is sports betting different from day trading or prediction markets?
What are the dangers of addiction, wasted time, and chasing easy money?