Uncommon investment structures: tontine

I spotted news of Tontine Associates, a Connecticut hedge fund that is down +65% this year. But what's a tontine? Apparently, it's an investment vehicle which combines features of a group annuity, group life insurance, and a lottery. Each investor buys a share, and the funds are then invested, which pay dividends. As the investors die, the shares are redistributed among the surviving members until the last one collects the principal. Turns out this is no longer widely used because:

• People realized they could sign children up for it early and collect dividends for much longer than expected. A similar problem has been encountered by defined-benefit pensions as average lifespans have increased substantially.
• Investors were incentivized for killing each other to bolster their own share

To some extent, this structure still exists today in the form of joint tenancy with rights of survivorship. You might also remember an episode of the Simpsons involving Grandpa Simpson and treasures from WWII that featured a tontine.