Assume you win the $800 million jackpot and lose 50% to taxes, you have $400 million left over. Gambling losses are tax deductible as expenses against gambling

Assume you win the $800 million jackpot and lose 50% to taxes, you have $400 million left over. Gambling losses are tax deductible as expenses against gambling winnings. Going with your scenario, if you spend ~$146 million and win ~$800 million, you'll be taxed on the ~$654 million profit. Off the top of my head you're looking at ~$400 million in after tax winnings. So the investors get their ~$146 million back and then take a share of the remaining ~$400 million.