Will Elon Musk post more than 400 tweets this week? More than 800? Estimate correctly and you could wind up with a nice chunk of cash if you were to back your opinion by buying shares on Polymarket.The sometimes controversial Polymarket is one of the internets prediction markets. Thats a fancy and fairly sophisticated way to put your money where your mouth is when you feel the urge to state an opinion on the internet. Even if your opinion is Ill bet Musk tweets more than 400 times this week.Indeed, the Musk tweeting market on the site is so active that its been given a top-level site link and repeats weekly. This weeks market, which ends on January 17, has already done over $1.9 million in trading volume and it routinely hits more than $1 million. Thats not to say youd win that much money. Your payout would depend on how many shares you bought should your tweet-volume guess prove true. (Polymarket did not respond to our request for comment on how much money this market has paid out.)Polymarkets Elon tweet prediction market.Image Credits:PolymarketSite records show its been a weekly market since at least June. And theres a second one where users can bet on the number of tweets ranging between 300 and 550+ in 25-tweet increments.The discussions on the market get serious, too, sounding somewhat like horse track gamblers talking about their pick of ponies. For instance, on Tuesday, user Rogu analyzed: Current tweets per day is at 50, on pace to hit 350. To get to 400+ hed need to average more than 65 per day for the remaining time. While that is a fair bit more, its not *that* much. With the upcoming Starship test flight he might be tweeting a bit more than these past few days.Rogu is referring to SpaceXs Starship Flight 7 launch, which is scheduled for January 15.The Polymarket Elon Musk tweets market volume in a given week.Image Credits:PolymarketPolymarkets main competitor, Kalshi, also has an Elon Musk top-level link, but it links to all sorts of wanna-bet type opinions on Musk, ranging from what his roles might be in the new administration to guesses about his future net worth. (People can no doubt bet or buy shares on those things on Polymarket, too.)But how much time Musk will spend on his favorite, personally owned social media site has been an ongoing favorite. And it has to be one of the silliest yet entertaining ways people spend their money on the internet.