It's a shared wallet. All the coins end up at the same address split into small amounts between 4 and 8 CLAMs each. Staking rewards are shared between investors. After a coin stakes, you can't move it for 8 hours or so (510 blocks). We currently have 372,667.28 CLAM in the wallet. 370,271.84 is available to withdraw, and 2,395.44 recently staked and will be ready to withdraw within 8 hours.

If everyone tried to withdraw at once, the last 2,395 CLAM wouldn't be available, and people would have to wait. Note that that's less than 1% of the wallet's balance, so not really a problem.

To see the system in action, take a look at this transaction. It's me tidying up the wallet - taking a bunch of deposits and change, and splitting it into a whole lot of 4 CLAM outputs at the JD address. You'll see "spent" after maybe half of those outputs. Most of those represent outputs that have staked. The "unspent" ones still haven't staked even though they've been trying for about 5 weeks now.