ソース:[1] Dave Portnoy sold Barstool Sports for $551M — then got it back for $1 — what to learn from this ‘great trade’ (https://finance.yahoo.com/news/dave-portnoy-s ...)[2] Penn Entertainment Sells Barstool Sports Back To Founder Dave Portnoy In Deal Rebranding Sportsbook As ESPN BET (https://www.forbes.com/sites/brianbushard/202 ...)[3] Barstool Sports Founder Bought It Back for $1—Here's Dave Portnoy's Net Worth Now (https://www.investopedia.com/barstool-sports- ...)